AT&T KEYone refuses to update

So I seem to be having an update problem with my Keyone. I searched through the forum for any similar topics, even on at&t's forums, and haven't found any answers for what I'm experiencing. If there is a similar topic then I sincerely apologize. But anyways, I purchased a used Keyone used last month and just recently noticed that it hasn't been updated all the way. A few days ago I updated it to AAR649 and whenever I try to check for updates, it just tells me that my phone is currently up to date. On at&t's Keyone support page there appears to be 5 more updates including the 8.1 Oreo update. I called customer support and they were useless, they told me that the newest update for the phone was actually 7.0 and not 7.1.1 which it's on. I went to my local at&t store and they didn't know what to do and told me to call customer service back. I've read a few posts about autoloaders and Sugar, and sugar looked like the only fix until I read about the passwords being changed.

Things I've tried so far:
-Factory reset 6 times in the past 3 days
-32 second reboot
-regular reboot
-clearing cache
-clearing google framework data
-changing date and time manually to try and force the update
-reset without sim then reset with sim inserted
-waiting actual irl days and checking again
-checking while on wifi, my neighbors wifi, and 4g data

The only problem I thought about was that maybe it's because my sim is an at&t prepaid sim, not a post-paid sim, but if that was the case then why did I at least get the AAR649 update?
I have a good 4G connection, and I'm always connected to my 5ghz network with 400mbps download speeds. If anyone has any insight whatsoever, I'd highly appreciate it. Maybe I haven't factory reset it enough times so I'll go ahead and give that another go.

Is it actually an AT&T KEYone that was originally purchased from AT&T or is it some other variant? Open your phone dialer and enter this code: *#837837# (*#TESTER#) and share your PRD.