Just came back to say it's been almost a month and no corruption to be seen. I see another potential fix has been posted since, but thank you gvtci for the fix, worked great.
I tried gvtci's fix on my Sonarr db a few days ago and so far so good. Really high hopes that this is the end of this longstanding headache.
Even if it doesn't turn out to be a lasting fix, it still seems to me like a better solution than restoring from backup.
Thanks for the tip