After a month on LineageOS, I switched back to MIUI because of some annoying bug (I was loosing data connection switching to 2G while under wifi and back to 4G while without).
I see GPS is still an issue even though they wrote it was fixed - this pissed me off.
In my case, using derek gordon's settings solved the problem (with TOPntp app), I guess there is no other way round.
As for this mi.com location settings, I wasn't able to find them as well, but
@linkser 's theory could be right.