Forgive me if this is a stupid question but wouldn't a more recent vendor patch level have some sort of bug fix or other security patch or is June 2018 the most recent vendor patch level Xiaomi released for Pie ? Just so no misunderstanding, not complaining just trying to better understand. See this link
I've updated to today's build and the February patch has come to LOS16, still double tap to wake isn't working. Could you please look into this issue @infrag? As I've said before, the changelog is showing some major changes for all the devices related to this, but it's not working fine for mi8.
Vendor patch level is just a field we fill in when compiling.
It doesnt actually mean thats the patch level you are running.
However I believe google does compare vendor patch level with the device fingerprint for CTS. Therefore it needs to remain the same as what stock has for this field.