I think this is not exclusively a Xiaomi.EU ROM issue
but I would like to share what is happening to me:
Phone, ROM and others:
Redmi Note 4 Snapdragon (but I think this is related to much more phones)
running on Xiaomi.EU Stabe V10.1.1.0
with Magisk 17.3 but it does this with 18.0 too (updated today)
(same has happened on at least 2..3 other Xiaomi.EU ROMs as well - and on Global stable & Global dev as well).
Issue description:
com.miui.securitycenter.remote keeps the CPU at 2GHz even though the CPU load is not too much (5..10%) and not letting the phone go sleeping at all. This is happening every time right after opening the Security app and starting a scan. Even if I stop it or leave it to finish it does this.. no matter what I do. It worked for like 2 whole days correctly but today morning I cought it again, running at 2GHz and not letting the phone sleeping.. plus the obvious: battery drain. Ah, and there's another one.
com.xiaomi.joyose - that's in foreground alllll the time.
Workaround:
I wiped the data of the Security app - but have no idea why it is coming back all the time.
I posted this already in this site some months ago under a different ROM version
[here - 8.8.9].
I have no idea what is causing this. Even without any Magisk mod it is doing this. No kernel tweaks or anything special.