Hello,
Thank you for posting in the Microsoft community forum.
It is recommended that you use full-screen mode instead of window mode when connecting to a remote desktop. If you are already in full screen mode, try exiting full screen mode and then switching back again.
I don't have a Citrix Receiver environment, and I recommend that you first check the display related Settings in the client Settings, such as DPI scaling or resolution Settings, and then make adjustments. Try setting the zoom mode to "No, use native resolution" and see if that solves the problem. Also, check to see if there are updates available for the Citrix Receiver.
If the problem persists and your Windows 11 system is Professional or later, you can try using Microsoft Remote Desktop to connect to the remote server.
I hope this helps.
Best regards
Jacen