Update notes 2021-05-20

- Changed: mission summary panels now appear after a small delay
- Changed: AP cost of RFX-BST 2 stimulant increased from 0 to 5
- Fixed: mechs getting destroyed with one shot from incendiary weapons
- Fixed: game freezing during AI turns
- Fixed: HUD flickering during some in-game cutscenes
- Fixed: problems with displaying some signs in Chinese and Russian fonts
- Fixed: a bug causing grenades to deal 1 damage to the throwing unit from time to time
- Fixed: lots of other minor bugs