UAPP pauses music playback when monitor/TV is turned off

I have been running UAPP (USB Audio Player Pro) with an Android TV box for years, and recently loaded it on to a Zidoo Z9X player to use an external DAC.
In both instances whenever I turn off the monitor/TV, which is connected via HDMI, the playing music is paused.
I have checked Settings in UAPP and in the Z9X and haven't found anything to prevent this.

Here is the response of the UAPP developer to my problem>
"Please see if you can turn off battery optimisation for the app in the Android battery section or Android Settings app -> Apps -> UAPP.
Other than that, please ask the manufacturer of the device."

Does anyone know how to access the battery optimization settings for an app in the Z9X???
Or any other solution???

Any help would be appreciated since I don't want or need the TV to be on all the time.

 

I had conversations with @Markswift2003 day ago with similar problem.

...when I turn off TV just to listen music on AVR, Z10 Pro changes resolution to SD and than back on 4K causing sound drop. Devices are connected as fallow - Z10 Pro (HDMI) Denon AVR x1200w (HDMI ARC) Samsung TV. Denon is capable of passing through 4k HDR, and I set Z10 Pro HDMI resolution 4K 60Hz (locked). ​

He advised me to save TVs EDID, that solved only resolution switching but audio drop remained.
It is interesting that drop doesn't happen when I turn TV back on.

 

In my case it happens whether it's a TV or just a computer monitor.