portainer: Editor stack content is not displayed completely.

Bug description After upgrading to 2.18.1 (EE) in a Single Node setup, the Stack details (compose file) is not displayed completely. The field for the content has the correct length, but after about half of the actual content only empty lines are displayed.

Expected behavior When opening the editor for an existing stack, the complete content of the compose file should be displayed. It worked before the update to 2.18.1 without problems. It makes no difference between a local Docker instance or a connected Edge Agent Docker environment.

Portainer Logs No relevant logs found

Steps to reproduce the issue:

1. call an existing stack
2. switch to the stack editor
3. scroll down in the stack, from half of the content only empty lines are displayed.
4. click on an empty area to reload a part of the content. The step can be repeated again and again until the complete content is displayed.

Technical details:

• Portainer version: 2.18.1
• Docker version (managed by Portainer): 20.10.3 (Synology NAS) and 23.0.4 (Ubuntu Server)
• Platform (windows/linux): Linux and Synology DSM 7.1
• Command used to start Portainer (docker run -p 9443:9443 portainer/portainer): docker run -p 9443:9443 portainer/portainer
• Browser: Edge and Chrome
• Use Case (delete as appropriate): Using Portainer at Home
• Have you reviewed our technical documentation and knowledge base? Yes

Additional context Add any other context about the problem here.