Speaker Issues on Hi9 Plus

Hello. I purchased the Hi9 Plus a few days ago and mostly everything has been great, except for the speakers. For some reason, audio will sometimes switch to one speaker rather than play through both at the same time. I was wondering if anyone else had experienced this, and if so, is there a fix? Any help is appreciated. Thanks!

Does it happen with any special application? If so, say which one to be able to do the test since I have not observed any change in the speakers in my daily use, especially when the sound is not stereo

It’s actually with all applications. I haven’t been able to test this completely, but it only seems to happen when the tablet is on vibrate.