Android/EMUI keeps disabling third-party texting application

Hello

I use MyPhoneExplorer to send/receive text messages with a Huawei P8 Lite that I bought recently.

MPE worked fine with my previous Android phone, but that new phone keeps prompting me with the following dialog (attached).

It seems to appear whenever the screens turns itself off.

Does someone know of a solution?

FWIW, the phone is running the stock software: Android 5.0 and EMUI 3.1.

Thank you.

Attached Thumbnails