I've had this issue crop up on past three character lives. last life, it happened the first run through PoP, I got ticked and recalled, reset and ran it a second - it did NOT bug on the second time thru. This life, it bugged on me, I DDoored and came back and had the same results previous posters did: could open up but lost the extra orbs. Luckily, I had run it in reverse order (top to bottom), so all other rooms were done at that point and I could complete.

Not a pretty workaround, but a workaround all the same.