Unstable robot needs rethinking

Hi there, distinguished readership.

I bought a Yahboom 6WD "all-terrain" rover through Amazon and built it over the last few days. It has an Arduino UNO R3 clone board, a Yahboom proprietary expansion PCB, 3 AM2857 motor drivers etc. There are two ways to control it: WiFi/cam module (Camera: GC0308, WiFi: SV6030P) and a Bluetooth module.

Images and tech specs at Yandex disk: https://yadi.sk/d/6herOBZqH6iYNQ?w=1

The problem is that the WIFI connection to the expansion board appears to be unstable. Even a faint jolt (and this rover has plenty of torque so it jumps around a lot) will knock it into a permanent spin one way (skid steering) or gets stuck on 100% accelerator. I have wired and rewired it over and over again and the issue doesn't go away. All wiring and specs available at:

https://www.yahboom.net/study/6wd-robot

My business idea depends on me allowing clients to pilot the rover and operate the PTZ camera remotely over 4G LTE and the WiFi app would have been the easiest way to accomplish that. So i have on hand 2 Arduino UNO R3 boards, 1 Arduino MEGA, 1 Raspberry Pi 4B 4GB with 7 inch screen, 1 Pixhawk PX4 autopilot, the brushed, geared motors that came with the 6WD and and the 3 motor drivers. I don't want to use Ardurover on the PX4 and MAVLink telemetry because the QGroundControl or Mission Planner GUI are way too complicated for non-tech savvy clients. I only need an app that allows you to point it at the IP and port numbers, two joysticks (rover and cam control) and live video.

Could somebody recommend the best and easiest software/hardware configuration with the equipment on hand that achieves my requirements? Will the motor drivers on hand work with my other hardware? I know Linux, TCP/IP networking and electronics (a bit) but am not a programmer (script kiddie). I've looked at Kodular and Blynk but am not sure if that would serve me well or waste my time.

Thank you very much for any advice.

Nick