Just out of curiosity, do you know when that payware was created?
This is why I’m hesitant on getting freeware/payware. The SDK right now is still a work in progress and if these developers do not keep up with those changes, it can break MSFS.
Soon, official 3rd Party Developers will get a pre-release of an upcoming patch to make sure their product still works.
As @MortThe2nd wrote, notify the devs of that payware to let them know. Glad you found the culprit!