I just noticed that autologin (top-level) doesn't work for me on the Wikitech wiki. I haven't tried logging in from scratch yet. It looks like our cookie hack from T389433: Fix stuck old cookies on Wikitech is not clearing the labswikiUserID cookie with the wrong domain for me, I don't know why. But it seems it's not just me: https://logstash.wikimedia.org/goto/7db8e655f0ee1cce3914a37521644c0c
(@Tgr and I have been debugging this)