Did the upgrade also break scrolling on their site?
Your ad blocker is probably blocking a modal popup, badly.
Why is a site that needs to be ADA2-compliant showing anything modal?
Does the ADA outlaw modals?
Blind people can't close them and it screws up their screen reader. Blind people often rely on public transportation.
Only if they’re badly implemented. Lots of fully accessible software has modal dialogs.