might be your smartphone browser/system is using some kind of proxy. this could explain that you are able to ping, but the browser shows access denied. if no log entries are generated on the server when trying to access it via browser, it has to be something on client side or inbetween. on grapheneOS check: Settings - Network and Internet - Internet - Wifi-Settings - choose edit at top right - then advanced. If proxy is not set to none, change it and test again.

If this still doesn’t help, my last bet is some kind of duplicate IP

I think very few people mind changing it

I doubt that. Do you know how many system configurations depend on these keywords? Do you have any idea how many hours of work and system outages this would cause?

What?! You are remembering that story wrong. She was a dolphin trainer or some scientist and jerked of the dolphin because she thought the dolphin was depressed and lonely.

Edit: Found the source https://allthatsinteresting.com/margaret-howe-lovatt

Here in Germany we had an ad for a “Tiefbauunternehmen” / “civil engineering company”.

The German name translates to “deep building company”. Their slogan: “Experten für untenrum” / “professionals for the parts down below”.

I hope the translation works