I am by no means an expert in the field of automotive HVAC, but I think your system is low on refrigerant. At 2000 rpm, ambient temp of 85 deg F, "normal" low side pressure should be 45 - 55 psi, and high side pressure should be 225 - 250 psi.
In watching your video, it looks like when the compressor engages, you are getting the pressures you cite at 2000 rpm - 13 on the low side and 225 on the high side. However, when the compressor disengages (what you call the 85 deg ambient air temp, the low side pressure rises and the high side pressure drops slightly, which is normal behavior.
Does this correlate with what you are observing relative to the compressor engaging and disengaging?
Is the cycling of the compressor frequent?
If yes, then you are likely low on refrigerant.
Here is link to a chart for R-134a Temperature vs Pressure and it includes some troubleshooting information: