I am fairly certain I know what the issue is, but wanted to validate my thoughts and see whether anyone had additional insight.
I recently purchased a Ridge Washer stubby gun off Amazon to replace the cumbersome wand that came with my Active 2.3 washer. The Ridge gun came with the proper M22 x 14mm adapter to connect the stock Active hose to the gun. I didn't use Teflon tape on the connections but did tighten the fittings prior to washing the car. During the wash, I noticed the Active 2.3 would occasionally surge. A quick 1 second surge every 1-2min when the trigger was off. I initially thought it was air in the system so I turned the washer off and purged the system. The water flow was continuous and I didn't notice any sputtering or air bubbles. I turned the washer back on and the surging still occurred.
To rule out any issues with my washer, I swapped the original Active wand/gun back on and the surging didn't happen. Now, it's worth noting, I always just hand tighten the hose to the Active wand and have been doing so for the past year I've been using it. No issues at all. I typically disconnect everything when I'm done using the washer. Additionally, I used the same nozzle on both the Ridge gun and the wand when troubleshooting to rule out orifice size incompatibility.
This leads me to believe it could either be a faulty stubby gun (ie: small pressure leak in the Ridge stubby gun) or a leak in the connections within the fittings between the hose and the gun? Ie: lack of Teflon tape use.
Thanks in advance for any insight. I want to narrow down the issue before I return the stubby gun as I really did enjoy using it!