This may fix the leak, if you want to try the change before the next beta.
Opus 11.13.1 beta needs to be installed first (link in my signature, if needed). Then fully exit Opus (via File / Exit Directory Opus) and, using Explorer or something that isn't Opus, copy the dopus.exe from this zip over your existing one in C:\Program Files\GPSoftware\Directory Opus.
(Test version removed, as the change is now part of 11.13.2 beta.)
Fingers crossed, and maybe we owe you that free upgrade now. 