"Reset On Enable" enabled OnTimer trigger works fine for first time.
After that, inactivate GameObject and re-activate it.This time OnTimer trigger fires too early. It does not reset its "started time".
You can see at wrld_1533bd7c-672d-47bf-bc9f-2a66b9771c55
It is marked as "COMPLETE". But this remains in latest release 2018.3.2p1.