diff --git a/ketcher-autotests/playwright.config.ts b/ketcher-autotests/playwright.config.ts
index 80ea617695..28eedacfe9 100644
--- a/ketcher-autotests/playwright.config.ts
+++ b/ketcher-autotests/playwright.config.ts
@@ -63,7 +63,7 @@ function baseURL(): string {
 const MAX_NUMBER_OF_RETRIES = 2;
 // const MAX_NUMBER_OF_FAILURES = 3;
 const isCI = process.env.CI_ENVIRONMENT === 'true';
-var numWorkers = os.cpus().length;
+let numWorkers = os.cpus().length;
 if (process.env.NUM_WORKERS) {
   numWorkers = Number(process.env.NUM_WORKERS);
 }
diff --git a/ketcher-autotests/tests/Macromolecule-editor/Copy-And-Paste/sequence-mode-copy-paste.spec.ts-snapshots/Sequence-edit-mode-After-pasting-between-two-n-4b8dc-pasted-fragment-is-merged-with-existing-chain-1-chromium-linux.png b/ketcher-autotests/tests/Macromolecule-editor/Copy-And-Paste/sequence-mode-copy-paste.spec.ts-snapshots/Sequence-edit-mode-After-pasting-between-two-n-4b8dc-pasted-fragment-is-merged-with-existing-chain-1-chromium-linux.png
index ffc07ff24c..01e4dff69c 100644
Binary files a/ketcher-autotests/tests/Macromolecule-editor/Copy-And-Paste/sequence-mode-copy-paste.spec.ts-snapshots/Sequence-edit-mode-After-pasting-between-two-n-4b8dc-pasted-fragment-is-merged-with-existing-chain-1-chromium-linux.png and b/ketcher-autotests/tests/Macromolecule-editor/Copy-And-Paste/sequence-mode-copy-paste.spec.ts-snapshots/Sequence-edit-mode-After-pasting-between-two-n-4b8dc-pasted-fragment-is-merged-with-existing-chain-1-chromium-linux.png differ
diff --git a/ketcher-autotests/tests/Macromolecule-editor/Copy-And-Paste/sequence-mode-copy-paste.spec.ts-snapshots/Sequence-mode-copy-paste-for-edit-mode-Copy-paste-selection-with-LClick-drag-and-undo-2-chromium-linux.png b/ketcher-autotests/tests/Macromolecule-editor/Copy-And-Paste/sequence-mode-copy-paste.spec.ts-snapshots/Sequence-mode-copy-paste-for-edit-mode-Copy-paste-selection-with-LClick-drag-and-undo-2-chromium-linux.png
index f1ef6d1ae1..1088f1fbff 100644
Binary files a/ketcher-autotests/tests/Macromolecule-editor/Copy-And-Paste/sequence-mode-copy-paste.spec.ts-snapshots/Sequence-mode-copy-paste-for-edit-mode-Copy-paste-selection-with-LClick-drag-and-undo-2-chromium-linux.png and b/ketcher-autotests/tests/Macromolecule-editor/Copy-And-Paste/sequence-mode-copy-paste.spec.ts-snapshots/Sequence-mode-copy-paste-for-edit-mode-Copy-paste-selection-with-LClick-drag-and-undo-2-chromium-linux.png differ
diff --git a/packages/ketcher-core/src/application/editor/modes/SequenceMode.ts b/packages/ketcher-core/src/application/editor/modes/SequenceMode.ts
index afebe22d5c..24ea7d2018 100644
--- a/packages/ketcher-core/src/application/editor/modes/SequenceMode.ts
+++ b/packages/ketcher-core/src/application/editor/modes/SequenceMode.ts
@@ -1040,8 +1040,7 @@ export class SequenceMode extends BaseMode {
     const currentSequence = SequenceRenderer.currentChain;
 
     const currentSequenceHasPhosphate =
-      currentSequence?.lastNonEmptyNode?.monomer?.monomerItem?.props?.Name ===
-      'Phosphate';
+      currentSequence?.lastNonEmptyNode?.monomer?.isPhosphate;
 
     let nextCaretPosition =
       SequenceRenderer.caretPosition + chainsCollection.length;
@@ -1050,6 +1049,13 @@ export class SequenceMode extends BaseMode {
       nextCaretPosition -= 1;
     }
 
+    const hasPhosphateAtChainEnd =
+      chainsCollection?.lastNode?.monomer?.isPhosphate;
+
+    if (!SequenceRenderer.isCaretAtChainEnd && hasPhosphateAtChainEnd) {
+      nextCaretPosition -= 1;
+    }
+
     const modelChanges = this.insertNewSequenceFragment(chainsCollection);
 
     modelChanges.addOperation(new ReinitializeModeOperation());
diff --git a/packages/ketcher-core/src/application/render/renderers/sequence/SequenceRenderer.ts b/packages/ketcher-core/src/application/render/renderers/sequence/SequenceRenderer.ts
index 48f9448f73..02de9ed942 100644
--- a/packages/ketcher-core/src/application/render/renderers/sequence/SequenceRenderer.ts
+++ b/packages/ketcher-core/src/application/render/renderers/sequence/SequenceRenderer.ts
@@ -945,4 +945,8 @@ export class SequenceRenderer {
       SequenceRenderer.chainsCollection.firstNode instanceof EmptySequenceNode
     );
   }
+
+  public static get isCaretAtChainEnd() {
+    return SequenceRenderer.currentEdittingNode instanceof EmptySequenceNode;
+  }
 }
diff --git a/packages/ketcher-core/src/domain/entities/BaseMonomer.ts b/packages/ketcher-core/src/domain/entities/BaseMonomer.ts
index 6b9f4ede91..1c686bee69 100644
--- a/packages/ketcher-core/src/domain/entities/BaseMonomer.ts
+++ b/packages/ketcher-core/src/domain/entities/BaseMonomer.ts
@@ -13,6 +13,7 @@ import assert from 'assert';
 import {
   IKetAttachmentPoint,
   IKetAttachmentPointType,
+  KetMonomerClass,
 } from 'application/formatters/types/ket';
 import { RnaSubChain } from 'domain/entities/monomer-chains/RnaSubChain';
 import { ChemSubChain } from 'domain/entities/monomer-chains/ChemSubChain';
@@ -329,6 +330,10 @@ export abstract class BaseMonomer extends DrawingEntity {
     return this.attachmentPointsToBonds[attachmentPointName] !== undefined;
   }
 
+  public get isPhosphate() {
+    return this.monomerItem?.props?.MonomerClass === KetMonomerClass.Phosphate;
+  }
+
   public get usedAttachmentPointsNamesList() {
     const list: AttachmentPointName[] = [];