I have an S9+, have run hotspot for years with no issue. Once I got the last Android update, it won't work. I chatted with Samsung support via FB Messenger (Steph was very nice!), she walked me through several things to try, all with no luck. Going to chat with AT&T next, but this all goes back to the latest Android update. Worked fine before, now it says my plan doesn't support Mobile Tethering, except it does, and I've double checked that. You need to get a fix out for this ASAP. From what I can gather while searching for fixes on the internet, it seems to be a widespread problem. You should have found this bug in beta testing before a general release. Get it fixed!! Send an update. This is ridiculous!!!!