No internet connection! Help!

I purchased my 2023 GMC Canyon on Saturday June 24th and have had internet issues ever since then. My Google maps bounces my location all over the place and goes haywire when I get close to a destination or do frequent turns. My wifi and internet is basically non-existent. When I run a speed test on a tablet that's connected to the OnStar hot spot I get about 3mbps download and the upload speed doesn't even register. I have created a case with OnStar and they have sent multiple refresh signals but none have worked. I also tried unplugging the negative to the battery for about 5 minutes and then reconnecting, that fixed the issue for about 10 minutes but then the internet went back down to its old slow speeds again. What is my next step or how can I resolve this? Very frustrating considering I just spent $50,000 on this truck.