Recently (I don’t know when it exactly started, but probably around the introduction of iOS 13) I’m unable to use a Personal Hotspot on my MacBook Pro, from either my iPhone or my iPad (with cellular capabilities). This worked fine in the past, but while the MacBook still connects to an iOS device, it will now not have any internet connection. I also tried using the hotspot from my iPhone on my iPad and vice versa, with exactly the same behaviour: connection, but no internet.
I have already emailed my provider whether they changed anything in my mobile subscription recently, but it usually takes them up to a week to respond.
I’ve tested it this morning, iPad with iOS13 works fine, mac with macOS Catalina does not the first time.
Needed to reboot and try twice more for it to have an internet connection
I just tried this on a 11” iPad Pro (WiFi) and there was also an issue connecting iOS devices (it just timed out and wouldn’t connect). I had to restart both the phone and and iPad for it to successfully connect. This worked perfectly on iOS 12, what a shame they’ve broken it in 13! After this, I tried on my MacBook and it worked first time, probably because I’d restarted the phone recently.
Thankfully I have a cellular 13” for when I’m travelling, and I only use the 11” at home.