My loop button has disappeared (in Jumpgate at least... I haven't checked non-jumpgate) since my last session last month. It's still there if I do an in-private browser tab. I saw an earlier topic that said "if you find out what extension might be causing the issue, let us know" and I only have one extension that interacts with Roll20.com : Beyond20 that allows my players & I to roll using D&D Beyond character/creature sheets.