Karcher K5 Washer: Low Pressure Issue when Releasing Lance

Hello,
The Karcher K5 washer does not turn on at full pressure, only when I release pressure on the lance. What could be the reason?

I had a washer k5.55 it was normal for me but after stopping work and switching it on again (using the button in the lance) it gave low pressure, it was necessary to disconnect the lance to pour out water from it and only then gave normal pressure, I undressed it all and the center of the valve was sealed such as wax, I think that it was cleaning the washer after washing the unwashed chemistry and I washed it all and works, now when I wash something with chemistry, after the procedure I put the hose from the chemistry tank into the water bottle and turn it on for a moment rinsed well and polka what works for now

The topic has been raised many times

https://www.elektroda.pl/rtvforum/search.php

I don't know for how long, but my advice was:
1. Connect the water hose
2. Detach the lance from the pressure hose - there is a yellow button on the lance for this (i.e. the pressure hose is connected to the washer)
3. Turn off the water
4. Wait 5 minutes (water is to drain normally from the pressure hose during this time)
5. Turn off the water
6. Connect the lance
7. Turn off the water
8. Turn on the washer
It should work
pozdr
Y

Hanys, what was with this washer because I have the same problem. I started everything up and it still does not run at high pressure.

Has anyone solved this problem?

firstly, check whether the washer turns on without the lance, on the gun itself, and after releasing the trigger it turns off the engine normally, this is important information for further diagnosis