I have a hisense roku tv, recently i have had issues with it connecting to wireless interent and then today it rebooted twice and then froze on the opening screen where it says hisense*roku tv. I have unplugged and plugged back in, didn't help. I hit the reset button and in the middle of updating it crashed and rebooted again only to be stuck on the opening screen again. Hisense says It's a roku issue but I can't find any thing on it and obviously can't contact an actual rep. This tv isn't even a year old.
Hisense isn't telling you the truth. Roku does not manufacture or sell TVs. They only provide the operating system. The TV manufacturer has to support its hardware, and it sounds to me like the TV has had a failure. I had an Insignia Roku TV that was stuck in the setup loop. Since it was brand new, I just returned it to Best Buy (Insignia is their house brand) and swapped it for a new one. The replacement has worked fine for years. Hisense should cover your problem. According to a quick search I just made, they offer a one year parts and labor warranty on their TVs. Here's the link to their US warranty page: https://www.hisense-usa.com/television-1-year-warranty
You can try leaving it unplugged for a couple of minutes. Then plug it back in and see if issue goes away.
If doesn't help, you can try factory resetting the TV using the pinhole (normally located near the ports or USB, location varies). You just press and hold until TV reboots into a Hisense startup screen.
Sometimes a visual helps. https://www.youtube.com/watch?v=CiHdONjuqfY
Hope that helps you.