Hello I bougth this device too
It is a little tricky, I guess...
I received it with a store modified rom. Try to change to a GSI one, but I got a infinite bootloop as result. Luckily, I can restore the official chinesse rom with the unbrick tutorial from @sso003
(thanks a lot!).
With that, I updated the official firmware from 555 to 697, and this the GSIs runs correctly. I tried a few of them: PE+, CrDroid, Evolution, Project Elixir and Lineage. But I can´t fix the issue with sms on any of them. The PE+ rom obtain sms at first boot, but when update anything or install a few apps, the funtion is lost (this is weird) I followed the tutorial for 4pda in russian and there for fix it, and neither was good.
For last I tried to change the kernel boot and path magisk (4pda tutorial) and bricked the phone again...
I am at the point of official 772 and I will try install GSI again (Chinesse ZUI is impossible to use for me) I hope have more fortune that before.