pico w/ Lipo shim power issues - no power at vbus pin

Hi all. I’ve added a lipo shin to my pico but I’m having power problems with it, basically it won’t power the pico as it should, details are below: The power out of the lipo connector is good (at source) Voltage at the 3v3en pin is good, this goes on and off with the button on the front of the shim. If I bridge power from the +ive on the back of the plug to the VBUS pin we get power and everything works as it should. However if I bridge from the 3v3en pin (same voltage) then the pico still won’t power on If I don’t bridge anything then there’s still power to the 3v3en pin but nothing to the vbus pin I’ve checked all soldered joints and I can’t see any issues. Does anyone have any ideas which pins I should check in particular or anything further I could do to trouble shoot?

A URL to the shim?