Rapture glich level wont save

Okay, I got a similar issue, but on a different chapter. I think I understood the pattern:

When you unlock a glitch level, it doesn't trigger a "game save" (due to a programmer oversight). So, if you unlock the level, start playing it for a while and then give up and quit; the level won't be unlocked when you come back because the game didn't save it.

A workaround is to play (and finish) some other (normal) levels after you have unlocked the glitch one.

(warning: everything above is my own speculation)

Would be nice to have this "bug" fixed, so that unlocked glitch levels are saved immediately.