What is happening:
going down the middle column of the seismic buck skill tree (except for the top one / base skill) the following glitched text is written for each upgrade:
Angers by {SplashEffects0Amount}.

Game client version:
2020.06.01

Screenshots:
https://cdn.discordapp.com/attachments/679777999742435358/792952296212398090/2020-12-27_22-08-00-4427.png