Just did another round of testing and found out I have a bad Tokarev mag (mashed-down feed lips).
Its not as loose as Soviet Tokarev mags, but will slide into a Romanian without binding, it catches, feeds, and releases properly,
I wonder if it was modified to work in a Tok, the release is a bit larger, its square instead of angled in. The seller said it had come with a Tokarev, so maybe it was done back when the magazines were incredibly hard to come by.
Will try to get it apart for cleaning and will get some more pics.