Extreme slowdown when using proprietary drivers in a large scene

As soon as we run this project with none mesa drivers the fps drops even on high end machines to a unusable level.

https://gitlab.com/kelteseth/qt3dlargesceneslowdownbug

Tested with Qt 5.12:
PC 1:
AMD Athlon 200GE with Radeon Vega Graphics
Ubuntu 19.04 mesa drivers
Runs very well

PC2:
AMD Ryzen 2700 + AMD Radeon 570
Windows 10 + AMD proprietary drivers
Runs slow when looking at all barells

PC3:
Intel i7 7700 + Nvidia 770
Windows 10 + Nvidia proprietary drivers
Runs slow when looking at all barells

PC3:
Intel i7 7700 + Nvidia 840m
Ubuntu 18.04 + Nvidia proprietary drivers
Runs slow when looking at all barells

Ubuntu 18.04 + Mesa
Runs very well