The trigger (or part of it) appears to have been sending the plugin last parameter data (FilterRecord parameters handle and/or the PsAPI 'data' handle) when it reshows its UI after being applied once. But the same data doesn't cause any issues when running without reshowing the UI. I don't know enough about FM's internals to be able to say what part of the global data could be causing the crash
Based on the UI angle and the stack traces of the debugger crash logs, I suspect that it may be a Win11 issue. I managed to duplicate similar bugs in older versions of PSFilterPdn and Paint.NET.
The fix in PSFilterPdn is forcing the filter to recreate its 'global' parameter data when reshowing the UI. This obviously will reset the UI to its defaults, but the plugin will load the correct parameter values from the Photoshop scripting data if it uses that.
Has anyone else encountered a similar issue with other plugin hosts on Win11?