Whilst using the Wayland session with Telegram in Wayland mode, the image preview is recognized as an independent window and as such will move to another workspace, clicking away won't go back to the main Telegram window.
This is a Wayland issue and after talking to Telegram devs they said it's not caused on their side.
Could it be possible to add exceptions to the extension so the preview feature isn't recognized by the extension or maybe force the closing of the preview window to shift back to main Telegram window?