I recently purchased a Ryobi pressure washer and paired it with an MTM foam cannon. I tried it out for the first time yesterday and had a few issues.
When I pulled the trigger, I got a decent foam mixture but it wasn't at full pressure. It was basically the equivalent of my foam gun. After about a minute of holding down the trigger, the pressure boosted and it seemed to work as designed. As soon as I released the trigger and pulled it again, I lost pressure.
This is the pressure washer:
https://www.homedepot.com/p/RYOBI-2-000-PSI-1-2-GPM-Electric-Pressure-Washer-RY141900/205566055