How to kill a wifi hot-spot?

Samsung Flip5, android, rural/remote area.
Had an interesting case of *hot-spot failure* that several hours of discussion with the (Telus) supplier's help desk was unable to solve! I'm new to smart-phones and use mine for mainly 2 things, these being its reason for existance: internet hot-spot and possible outgoing emergency calls. The contract says XY gb's of data per month at high rate and the rest at low. Because of topography and antenna distribution the low-rate never works but the high one usually got me up to 4-5 Mb/s. During times of medium to heavy precipitation in the direction of what I suspect is the source antenna (about 50 km over water) reception starts to falter. Last month I maxed out the quota so were it not for my wife's phone I would have ended up with no internet for 4 days. Time for the beef.
All of a sudden, no connection, so next day I got on the blower and they guided me step-by-step through TS for quite a while, none of it resulting in any kind of fix. My wife's phone continued delivering so the issue was in or with mine. We broke for lunch and then I had the idea to do a factory reset, which worked. I'd like to FIND the actual cause and be able to repeatedly DUPLICATE the problem so as to avoid it in the future, hence this post.
I'd appreciate a short list of possible suspects although to my way of thinking IF I am able to select hot-spot ON then there should be nothing else to do or not do on the phone-side. If there is then the hot-spot slider should be ghosted (which it never was).