Wired audio cutting out after around two hours

[some_random_person]

I use my phone to play the sounds of wind and rain to help me sleep at night. It's usually plugged into my speakers to do it. However, a while ago audio started cutting out, usually after around two hours (perhaps exactly but I'm not concious enough at night to check that). The app playing the sound behaves as if it was still playing but there's no sound coming from the speakers. I can only resume playback by unplugging the jack and plugging it in again.
At first, I thought that it's a problem with the app but the same thing is happening with another one. The speakers are all right too, nothing happens during the day, when they're connected to my laptop. Same thing is happening with my wife's phone, which is also a zenfone 3max. It does not happen when I'm using a bluetooth speaker.

It's supremely annoying, the sudden silence wakes me up quicker than any unexpected sound. What can I do with that?

 

[N4Newbie]

What is the name of the app?

 

[some_random_person]

The app I'm currently using is called Rain Sounds ( https://play.google.com/store/apps/details?id=net.metapps.watersounds&hl=en ), the one I used before is called A Soft Murmur ( https://play.google.com/store/apps/details?id=com.gabemart.asoftmurmur&hl=en )