Im testing now a setup with activities (Plasma 5.20.5 on MX linux21). As an introductory remark I notice that setting up activities makes sense only when start up sessions are not empty but instead saved from last usage state prior to shutdown/logoff or alternatively a stored state.

1. When I set up two instances of a browser (in the test case: Falkon), one to the first activity and the second to the second activity, both browsers with individual tab contents (URLs), this works fine. Until... I log off and log in again. Then both browser windows appear on the same activity.
   
2. Using two instances of Dolphin works fine, also when each of them are set to a distinct (opening) working directory. The same applies to Konsole.
   Krusader however, fails to keep disctinct tab directory settings on each of the instances in distinct activities (which is not really surprising, because on opening two instances on one single desktop prior to testing activities was already known to behave so). I'd like to continue using Krusader in an environment with several activities because of its strengths over Dolphin.

Any hints would be highly appreciated.