Headphone jack issues with Doogee X5 Max Pro

Hi,

I recently bought a Doogee X5 Max Pro phone for a relative from Amazon. He had issues with it freezing and shutting down, as well as a particular issue where, when he plugged certain things into the headphone jack, it would keep disconnecting and reconnecting (causing the music to pause). We returned that one and got a replacement, thinking that would solve the issues. It did solve most of them, but the new phone also has the problems with the headphone jack. I suspect it's a hardware issue, as no matter what I do (different music apps, clearing cache/data, even trying 'soundabout') the problem persists. This doesn't seem to happen with headphones, only with jack plugs such as one connects to an aux input. So for his car, hi-fi, speakers etc.. We've figured out a temporary workaround by connecting a bluetooth receiver to the aux inputs, but obviously it's not ideal to have to find workarounds. What I'm wondering is; could this be a phone-wide issue, or have we been unlucky with these two phones? As we're considering returning this phone and getting a different one altogether. Also, if it's not a 'quirk' of the phone, is this something fixable?

I got him the Doogee X5 Max Pro as I myself have an X5 Pro, and have been really happy with it personally, but it's rather a let down if it has an issue like this. My phone has been perfectly fine with all the cables/connections that his has an issue with.

Any ideas?

Thanks in advance,

Skye