Stock ROM for the 32GB version that we know. Please try to be a bit patient, if that's a real UMIDIGI S2 Lite, we will get the compatible ROM in a few days.
I'm still waiting for your seller's link - to help our investigation.
i can delete and add new face without any issue, its all saved ok, but after reboot, device can be unlock with face id (can not unlock with fingerprint after reboot), I can not set "after shutdown only password interface can unlock"
I don't know that seller (not on the available list of Amazon sellers) but I'm trying get the currently valid list. That wechat contact you shared is responsible for gearbest.com.
A flash tool ROM for the 64GB S2 Lite will be available today, in less then 24 hours.