The problem only occurs when I use NiceCrew.digial in Safari browser over VPN. I'm fairly sure it's a problem with the Soapbox software (Alex Gleason himself has told me it's a clusterfuck), not the hosting. I can't prove anything because I can only see things from the client end. The problem doesn't occur when I access the site directly or through iCloud relay. I'm not sure what there is between Soapbox and the VPN that causes this, and I'll never have insight to that. All I know is, when I ask any one link in the chain about the problem, the response is, "not me", when I get a response at all.
Safari is the browser engine on Macs, iPhones, and iPads. It's about 1/3 of marketshare in the US, second after Google Chrome. It's completely standards compliant and macOS is the most popular and successful desktop Unix variant ever. There's no reason it shouldn't be properly supported.