hotspot connection

iphone 12 mini running 16.0.3. yesterday i tried connecting my hotspot to my devices in my home like i have everyday for the last 3 years. but only this time the devices would claim to be connected with good connection but once trying to load any apps it will not work. when trying the internet on an app like snapchat it loads the newest up to date stories at the time, but will not open or play any of the snap story’s. it is like this on every device i’ve tried in and out of my house. i’ve also tried connecting to it in a different section of the city and no difference. after calling apple i visited att which gave me the same response apple did. “we don’t know”. at this point apple and att both claim to not know the issue but are ok with taking my money for the bill still. i’ve reset network settings twice and every single other trouble shoot apple and att could offer. i have another device on the same plan. it’s an iphone 8, the hotspot on that phone works flawlessly, on the same devices unable to work on my own hotspot. i rely on this hotspot to run my small business and having an issue like this can be massive.