I know this is a late reply but the solution to Dexpot ungrouping can be solved by editing the wechsel.ini file inside the C:\Program Files (x86)\Dexpot folder.
Inside the exe section just add any program exe that you dont want ungrouped. Most apps like explorer already have 'move' applied in the klasse section by default. Alternatively you can add by class or by title but exe covers all windows, so your choice. There is an article on the dexpot website what move, ignore, sticky and other operators do, just search for dexpot and wechsel.
PS: if you are editing wechsel.ini while dexpot is running you will have a problem saving, best way is to edit with Note++ started as administrator, edit, save and restart dexpot.
Example
[Exe]
GroupyCtrl.exe=move
chrome.exe=move
msedge.exe=move
code.exe=move
