My family got the HiPad X Pro a couple of months ago for my sister. Originally, she was able to play Roblox with no issues. Today suddenly, it will not allow her into her account anymore. It is not roblox as we can log in to her account easily on the phone, computer, or chrome app, but when we attempt to log in on her tablet, we either can’t log in and do not get an error message, says “something went wrong, try again later”, or a message saying “unknown error”. It allowed us to log in with a new Roblox account we created this morning, but we would really like her to be able to access her original account on the tablet. We are not sure why it will not let her as there was no issue yesterday and we can log in to other accounts with no issue.
serial number: ZHipXpEY00231209204
we bought it on amazon a couple of months ago
Did you try to update the roblox app trough the Google Play Store?
If so, a simple restart of the device can go a long way whhen it comes to weirdly buggy devices.
We checked the play store already, and there was no option to update. We did, however, uninstall and redownload it multiple times. We also restarted her tablet multiple times as well as doing a factory reset of the tablet before posting with no resolution. She was able to play earlier, but only after making a completely new account. Still unable to log in to her original one despite that. It’s very weird.
Yeah, at that point I think it is a Roblox issue, and not tablets. Maybe something with the account is messed up? Either way I think Roblox support is of more use in your situation.
The only suggestion i can think of is in case ROBlox cannot solve your problem, would be to reinstall the system and the download all clean apps and see if that would help
It’s strange, but the exact same thing happens to me, it’s been 2 weeks that I haven’t been able to log in with my usual username to Roblox from my Chuwi Hipad XPro, I thought it was the tablet version, I’ve done several updates, hard reset and after looking at this post, I just put a new account in Roblox and it runs without problem, the problem is as the colleague says, the game doesn’t work with an old user, what’s happening?
Yes, that’s about how long our issue has been too! My sister has been playing on her new account, but she wants her old one back 
I contacted Roblox as well but haven’t heard back yet.