Who I have the same questioned this topic

I am devastated. I noticed in August my Galaxy S9 would not start the mobile hotspot, a feature I need as I am a traveling person who is a web developer.

They said it was going to be fixed in the next update. NOT! last week I went to use the Hotspot, and same error as the title of this post (Unable to Connect Authentication Error).

I called and after bout an hour of fudging with things they said they were going to send me a completely new phone - a Galaxy S10e - well guess what!?? SAME ISSUE after all the hours of pleading with Verizon and the total inconvenience of waitying for the new phone and setting it up again with all my apps, wiping my old phone and getting this error again, is enough to make me lose my mind. 

I wish I had tested the HotSpot BEFORE i wiped my old phone 

This is telling me it is indeed NOT a hardward issue but something wrong with my Verizon account!

I am about to eat the contract and switch to another provider after being a dedicated Verizon custonmer for over 10 years.