Plank issue with app selection

Running 20.04, fresh install (overwrote 19.10)

Last round of updates (although it might just be co-incidence), when I launch say chrome (and perhaps subsequent other apps) from Plank, if i then use that app just launched then all seems fine, but if say I launched Tilix, then i launch Chrome and then go back to the Tilix icon to bring that app active it does but as soon as i move off the plank icon it also removes the app from the foreground and the only to get to it is to close the other windows.
The icons are all marked as “keep in dock”, all other functions work fine aka if I RC then i can open another instance etc

hope that makes sense.