My washer does not spray the cleaner solution as high as it did originally. The high pressure spray is fine.

If your pressure washer works like ours, it has a T connection.
A plastic hose comes off the T and goes into the bucket of cleaner
Pressure from the hose creates suction across the T and this draws cleaner into pressure hose
The plastic hose from cleaner connects to a small brass ball valve on the T
The ball valve clogs up or changes over time and cleaner will not draw up into the pressure hose.
We would replace the valve stem
I don't know if they sell the little replacement parts like they used to

Finally we had so much trouble.
We started applying our chemical with a pump-up sprayer.
For us, it was cheaper, and the work went faster.
We put one guy on the pump up sprayer
And then another guy came behind him on the washer.