Server error 520 only when using Chrome on iPhone

Cannot login in to Practiscore using Chrome on an iPhone for the last several days. I can use Safari or embedded browser via other apps with no issues. Constantly getting Cloudfare server error 520.

I’m getting the same thing but using Chrome on a PC. From the same PC using a different browser (Edge) works. Connecting from a different PC using Chrome works. Connecting from Chrome on this specific PC does not work.

Anyone have any guesses? Cleared cache and cookies, deleted history, tried typing variations of the web address, with and without https:// (link copied from Edge browser didn’t work either).