After reading the link from OnePlus community, it looks like the person has issue connecting to the Wifi using OnePlus8.
Thank you guys for the reply. I haven’t done the network reset nor factory reset, I was hoping not to do that. From the link https://community.oneplus.com/thread/1326793450099572740 it looks like it didn’t help. I’ve tried to reset Access point names and set the 5g network mode to either NSA mode or NSA + SA mode but neither of them worked. I took it to the local T-Mobile store and they couldn’t fix it but they wanted me to buy a new phone lol. I haven’t tried to upgrade to a new SIM card, I bought the SIM card when I bought my phone so it is over 3 years old.
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