Wands sometimes have non drip valves behind the jets, they have a spring & ballbearing. The spring can become weak so don’t push the ballbearing hard enough to seal the jets .... gently stretch the spring
The same system is used in the wand trigger, a spring keeps the ballbearing pressed against the seal to stop flow, when you press the trigger it pushes against the spring and opens the flow, this spring can weaken and not close.... so leaks. ..... buy a seal kit