MIUI 11 has an issue with this tasks permission.
The tasks apk I use can't synced due to a permission issue :
None of the apps like davx or open tasks can gain rights to read task.
READ_TASKS: denied
WRITE_TASKS: granted
I can confirm the issue. Got it since we turn to MIUI 11. There were no issue on MIUI 11.
As b0wtie this is very anoying for me as I use a lot task to organise my work... :/