diff --git a/web/core/components/issues/issue-modal/base.tsx b/web/core/components/issues/issue-modal/base.tsx
index 0e4e3d6c39..cb638da638 100644
--- a/web/core/components/issues/issue-modal/base.tsx
+++ b/web/core/components/issues/issue-modal/base.tsx
@@ -3,7 +3,7 @@
 import React, { useEffect, useRef, useState } from "react";
 import { observer } from "mobx-react";
 import { useParams, usePathname } from "next/navigation";
-import { EIssuesStoreType, ISSUE_CREATED, ISSUE_UPDATED } from "@plane/constants";
+import { EIssueServiceType, EIssuesStoreType, ISSUE_CREATED, ISSUE_UPDATED } from "@plane/constants";
 import { useTranslation } from "@plane/i18n";
 // types
 import type { TBaseIssue, TIssue } from "@plane/types";
@@ -17,6 +17,7 @@ import { useEventTracker, useCycle, useIssues, useModule, useIssueDetail, useUse
 import { useIssueStoreType } from "@/hooks/use-issue-layout-store";
 import { useIssuesActions } from "@/hooks/use-issues-actions";
 // services
+import { useIssueTypes } from "@/plane-web/hooks/store";
 import { FileService } from "@/services/file.service";
 const fileService = new FileService();
 // local components
@@ -65,8 +66,10 @@ export const CreateUpdateIssueModalBase: React.FC<IssuesModalProps> = observer((
   const { issues } = useIssues(storeType);
   const { issues: projectIssues } = useIssues(EIssuesStoreType.PROJECT);
   const { issues: draftIssues } = useIssues(EIssuesStoreType.WORKSPACE_DRAFT);
-  const { fetchIssue } = useIssueDetail();
+  const { fetchIssue, removeSubIssue } = useIssueDetail();
+  const { removeSubIssue: removeEpicSubIssue } = useIssueDetail(EIssueServiceType.EPICS);
   const { handleCreateUpdatePropertyValues } = useIssueModal();
+  const { getIssueTypeById } = useIssueTypes();
   // pathname
   const pathname = usePathname();
   // current store details
@@ -260,6 +263,14 @@ export const CreateUpdateIssueModalBase: React.FC<IssuesModalProps> = observer((
     if (!workspaceSlug || !payload.project_id || !data?.id) return;
 
     try {
+      // check for parent change
+      if (data?.parent_id && payload?.parent_id && payload?.parent_id !== data?.parent_id) {
+        const isParentEpic = getIssueTypeById(data?.parent_id || "")?.is_epic;
+        if (isParentEpic)
+          await removeEpicSubIssue(workspaceSlug?.toString(), payload.project_id, data.parent_id, data.id);
+        else await removeSubIssue(workspaceSlug?.toString(), payload.project_id, data.parent_id, data.id);
+      }
+
       if (isDraft) await draftIssues.updateIssue(workspaceSlug.toString(), data.id, payload);
       else if (updateIssue) await updateIssue(payload.project_id, data.id, payload);
 
diff --git a/web/core/store/issue/issue-details/sub_issues.store.ts b/web/core/store/issue/issue-details/sub_issues.store.ts
index c2c160c390..e578057e3a 100644
--- a/web/core/store/issue/issue-details/sub_issues.store.ts
+++ b/web/core/store/issue/issue-details/sub_issues.store.ts
@@ -282,7 +282,7 @@ export class IssueSubIssuesStore implements IIssueSubIssuesStore {
       set(
         this.rootIssueDetailStore.rootIssueStore.issues.issuesMap,
         [parentIssueId, "sub_issues_count"],
-        this.subIssues[parentIssueId].length
+        this.subIssues[parentIssueId]?.length || 0
       );
     });
 
@@ -319,7 +319,7 @@ export class IssueSubIssuesStore implements IIssueSubIssuesStore {
       set(
         this.rootIssueDetailStore.rootIssueStore.issues.issuesMap,
         [parentIssueId, "sub_issues_count"],
-        this.subIssues[parentIssueId].length
+        this.subIssues[parentIssueId]?.length || 0
       );
     });
 
diff --git a/web/ee/components/issues/issue-details/parent-select-root.tsx b/web/ee/components/issues/issue-details/parent-select-root.tsx
index 8cc3fff5f6..8b3960c6de 100644
--- a/web/ee/components/issues/issue-details/parent-select-root.tsx
+++ b/web/ee/components/issues/issue-details/parent-select-root.tsx
@@ -31,11 +31,11 @@ export const IssueParentSelectRoot: React.FC<TIssueParentSelect> = observer((pro
   } = useIssueDetail();
   const {
     toggleParentIssueModal,
-    removeSubIssue,
     subIssues: { setSubIssueHelpers, fetchSubIssues },
   } = useIssueDetail();
   const { getIssueTypeById } = useIssueTypes();
-  const subIssueOperations = useSubIssueOperations(EIssueServiceType.EPICS);
+  const subIssueOperations = useSubIssueOperations();
+  const epicSubIssueOperations = useSubIssueOperations(EIssueServiceType.EPICS);
 
   // derived values
   const issue = getIssueById(issueId);
@@ -47,11 +47,15 @@ export const IssueParentSelectRoot: React.FC<TIssueParentSelect> = observer((pro
       const issueBeforeUpdate = { ...issue };
       const oldParentDetails = issueBeforeUpdate?.parent_id ? getIssueById(issueBeforeUpdate.parent_id) : undefined;
       const isOldParentEpic = getIssueTypeById(oldParentDetails?.type_id || "")?.is_epic;
+      if (oldParentDetails?.id) {
+        if (isOldParentEpic)
+          await epicSubIssueOperations.removeSubIssue(workspaceSlug, projectId, oldParentDetails.id, issueId);
+        else await subIssueOperations.removeSubIssue(workspaceSlug, projectId, oldParentDetails.id, issueId);
+      }
+
       await issueOperations.update(workspaceSlug, projectId, issueId, { parent_id: _issueId });
       await issueOperations.fetch(workspaceSlug, projectId, issueId, false);
       if (_issueId) await fetchSubIssues(workspaceSlug, projectId, _issueId);
-      if (isOldParentEpic && oldParentDetails?.id)
-        await subIssueOperations.removeSubIssue(workspaceSlug, projectId, oldParentDetails.id, issueId);
       toggleParentIssueModal(null);
     } catch (error) {
       console.error("something went wrong while fetching the issue");
@@ -65,14 +69,14 @@ export const IssueParentSelectRoot: React.FC<TIssueParentSelect> = observer((pro
     issueId: string
   ) => {
     try {
-      const issueBeforeUpdate = { ...issue };
-      const oldParentDetails = issueBeforeUpdate?.parent_id ? getIssueById(issueBeforeUpdate.parent_id) : undefined;
-      const isOldParentEpic = getIssueTypeById(oldParentDetails?.type_id || "")?.is_epic;
+      const parentDetails = parentIssueId ? getIssueById(parentIssueId) : undefined;
+      const isParentEpic = getIssueTypeById(parentDetails?.type_id || "")?.is_epic;
       setSubIssueHelpers(parentIssueId, "issue_loader", issueId);
-      await removeSubIssue(workspaceSlug, projectId, parentIssueId, issueId);
+
+      if (isParentEpic) await epicSubIssueOperations.removeSubIssue(workspaceSlug, projectId, parentIssueId, issueId);
+      else await subIssueOperations.removeSubIssue(workspaceSlug, projectId, parentIssueId, issueId);
+
       await fetchSubIssues(workspaceSlug, projectId, parentIssueId);
-      if (isOldParentEpic && oldParentDetails?.id)
-        await subIssueOperations.removeSubIssue(workspaceSlug, projectId, oldParentDetails.id, issueId);
       setSubIssueHelpers(parentIssueId, "issue_loader", issueId);
     } catch (error) {
       setToast({