Some of those regulators need adjusting during flow, try that…
I think most of us would have to ‘see’ it to help you much. The inside diameter of the tubing is 6mm, so I find it hard to believe you have a restriction on the compressor side smaller than that.
Does it drop immediately or take time to drop to that pressure?
How long are you operating when this happens.
Do you have ‘tank’ pressure to see if the tank is empty and you are running on the compressor only?
