@texxaport , did you get the global model or the one for the local market? If you didn't get the global model, you will have mostly 3G connectivity. I think on LTE, you will only have band 5 compatibility.
@texxaport I have a Chinese version of Note 8. It works perfectly with PM. I think your 9S will not have any issues as well.
This is is off their specs page for Global Version. Not sure what the difference is for any local market ones though.
Xiaomi Redmi Note 9S Global Version (6GB+128GB)
2G: GSM B2/B3/B5/B8
3G: WCDMA B1/B2/B4/B5/B8
4G: FDD-LTE B1/B2/B3/B4/B5/B7/B8/B20
SIM Card Slots: Dual SIM Card Dual Standby (Nano-SIM), Supports 2+1 card slot, nano-SIM + nano-SIM + TF