I have the same problem with P10 (not plus). Legit UK retailer (John Lewis) bought Feb 2018, still on B120 March 1st 2017.
Hadn't noticed the Serbia thing but mine has that too.
The suggestion to use the updater app doesn't work. Huawei said to try the Hisuite app (didn't work, said B120 is latest), and then said I sent it in for 2 weeks and they will update, but it will involve factory reset. Not thrilled about that, so might try to return it based on Serbia thing.
How do you find the latest approved firmware?
If I want to go for B162 how do I find the right version in firmware finder? I see 2 FullOTA-MF, one on 2017.09.30 another on 2017.08.14. How do I know which to use?
Whats the latest one thats safe to try?
Will I ever get back onto a supported OTA upgrade path or will it be like this always going forward (manual updates)?
Thanks