Just as the title says, whenever it comes time to pay colonists, the game will freeze for as long as 2 minutes before resuming like normal. (I've also experienced as long as 3-5ish minutes) The same thing happens when issuing a stimulus package, but the freeze doesn't seem to be as long (as far as I've noticed)
It's gotten worse as my population grows. Probably started at 2,000, and now that I'm just over 9,000 its gotten way worse. Unfortunately i just started playing (again, new account and new game data) so i can't say if its changed with updates.
I've experimented heavily with different performance settings, with little change.
Device: Samsung galaxy s9 (Snapdragon) Android Pie official beta program)
App version: v.0.78.0
Edit: also, as the pay freeze issue has gotten worse, so has colonists not working despite having jobs, being educated, having housing, and having+95% approval.