This is a problem, indeed.
My son has HUAWEI Y560-L01. Today he has been playing almost an hour and it seems he has 50 minutes out of an hour left. Seems the time limits can't be trusted at all.
F-Secure SAFE version 17.2.0013789
Android version 5.1.1
it is not guaranteed that time limits always work, sometimes there are some glitches or issues so the remaining time is left even after use of pre-set time, i hope they will fix this issue.
Please have a look at this KB article and change it in Battery manager settings to see if that solve the time limit issue.
If the above does not help, please try following steps on your Huawei phone:
1. On your Huawei phone, go to Settings , tap Apps & Notifications -> Apps -> Settings -> Special Access -> Ignore battery optimisation -> F-Secure SAFE -> "Allow (May drain your battery more quickly) -> OK.
2. On your Huawei phone, go to Settings -> Apps & Notifications -> Apps -> Settings -> Special Access -> Write System Settings -> IF F-Secure SAFE is there, click it -> "Allow write system settings".