Hictor

It did allow us to select an arrival time but they've just answered the DM we sent earlier on Twitter/X and it looks like they're still working on the arrival times : Hi, we had the team look into this issue. It seems there was an outage which may have affected guest's ability to complete online check-in but this is resolved and the online check-in is open now. However the arrival time slots have not yet been added, so you won't be able to complete the entire online check-in process yet. The team have requested for the arrival times to be added, so hopefully this will be uploaded soon.

Managed to check in on the app a few minutes ago so hopefully it's now working for everyone else.

Having the same problem with May 6th on Solstice. Different devices give the same error "Check-in has checked out". There doesn't seem to be a browser based check-in available just the message "We’ve gone mobile! Check in on the app".