KDE windows rules and no activities names in settings

I would like to start a few of my daily applications automatically during startup and assign them to proper activities. Currently I use 4 activities: - Internet (Chrome), - communication (Thunderbird and some IM), - settings (ksysguard, TeamViz and alike) and - terminals. I tried to use kwin advanced windows rules. But unfortunately, on the Size & position tab, after setting Activity to Apply initially, I am left with two possible activities - an empty field and - All activities Why are the names of my activities not shown?