What's New in Solid Edge 2022 says Object/Action workflows have been enhanced in this version allowing the user to pick the item to be acted upon prior to picking the command. It is not clear how this would be used with Trim Corner.
Solution
You need to pick one of the lines to be trimmed, select the command, then pick the other line to be trimmed.
Notes and References
Hardware/Software Configuration
Platform: INTEL
OS: windows
OS Version: 1064
Product: SOLID_EDGE
Application: PROFILE/SKETCH
Version: V222MP3
Function: MANIPULATION
Ref: 001-10284196