Newly waxed chain, skipping in gear 12.

Waxed my chain two days ago, going from oil to wax, after a thorough cleaning of the chain. I have no problem running it in gear 1-10, but 11 is occasionally skipping, and 12 is skipping all the time. I rode for 45 minutes on the bike yesterday, all in the lower gears with no issue, and it was running quite smoothly.

I have micro-adjusted with no success, and I have adjusted the h-limit screw, also with no success. Any ideas on what the issue could be? I didn't have this issue when using oil-based lube.

My setup is 1x-12 SRAM Rival.