Which LTE networks do China Smartphones support?
Most Xiaomi, Redmi, Realme, Oppo, Vivo, Oneplus and Meizu smartphones support band 1 and 3 ( frequency 1800MHz and 2100MHz ). This is sufficient for LTE reception in most EU countries.
In Germany, LTE is also transmitted in band 20 (frequency 800 MHz). This frequency is used by some providers in rural areas and so you will usually be downgraded to HDSP+ / UMTS. Global versions of the devices also offer band 20 (frequency 800MHz).