Using seamless mode on Debian with XFDE leads to windows competing to steal focus

In the latest version (flathub 921deaabd8bd653ea22f33fe9aaf1849a29aee6bbf2bade50f16555314468ffd), when there is more than one window open in seamless mode, switching between one window and another leads to all thincast client windows competing to steal focus from eachother. This results in cycling of focus between windows (so the title bars flash - I also have a sidebar window manager that I wrote for myself that keeps the windows in the list and if this is running at the time the selected item, which determines the active window, rapidly switches between the open thincast client windows until the focus-stealing stops). The more windows that are open, the longer this runs. By the time I had 5 windows open, it was effectively a neverending loop and I had to go to a different session to kill thincast client.

Reverting to 73a6647f9528f3aba8e02ac32b053be0987509fde5f5682933f41f5fa9802a15 fixes the problem.

The same issue happens in the latest snap.

Reproduce the focus-cycling behavior on Debian with XFDE in seamless mode using multiple windows, first comparing the reported Flathub revisions 921deaabd8bd653ea22f33fe9aaf1849a29aee6bbf2bade50f16555314468ffd and 73a6647f9528f3aba8e02ac32b053be0987509fde5f5682933f41f5fa9802a15. Check the same scenario in the latest snap. Done means switching between windows no longer causes repeated focus stealing or title-bar flashing.

Written by the indexing model from the issue text.