I'm currently on rooted (via magisk) Stable MIUI Global 9.2 (9.2.5.0) i wanted to flash EU rom for my Redmi 4x (3/32) (Santoni) will i lose my root and needed to root my phone again if i ever flash the EU rom?
Yes, of course, you need to flash root files after every ROM flash. What's the problem?
Xiaomi.eu ROMs are unlocked, so just flash ROM and root right after it.