Maui Linux (Tuned Ubuntu 16.04 fork with KDE Plasma)

http://nimb.ws/Xlv2U8 (Tranquility was hard to hit first time)
http://nimb.ws/Oin4Zo (But it works with items when it was clicked and scrolled to this place)
http://nimb.ws/nbogey

Bug isn't present in small window mode when buttons higher than ~60px from bottom of screen. When less - buttons isn't active. So it can be OS or Plasma related problem, but I haven't seen any similar in other games.