FWIW, I used to use my Google Nexus tablet rather than a cell phone. For unknown reason now I get broken video that is impossible to use during flight. Switching over to my Samsung Galaxy S9+ it works perfectly. Naturally, these use two different cables from the two different ports from the controller.
If your video recordings are happy, but your device display is breaking up, and you have shut down all background apps on the device, then yes, it could be the cable, (not all are created equal) you need a real data cable,
another issue could be the version of DJI GO4 app you are using. If you have recently updated "stuff", like the app, or tabby/phone device, you might have to rev back down to a previous version that is stable.
Also, try the port on the bottom of the controller to the device of choice.
Here is a link for the previous versions of the GO4 app.