Is this moon on a stick stuff? There seems to be a shortage of short sleeve cycle jerseys other than roadie types. I'm after a top with a zip so I can vent, but loose round the waist (not elastic or grippy). Not fussed about rear pockets or not. So like a cross between a running type t-shirt and cycle jersey.
Is that a real thing?
Look at Gravel jerseys (yes, really). They are often a looser fit.
I have a couple that are just that - Berghaus or Montane.
Longer cycling jerseys they are not.
I also have two Pearl Izumi 'traditional' short sleeve jerseys with the sticky bits on an three pockets (full roadie...) but actually are not that tight and work really well. ANOTHER EDIT: as scotroutes says, they are from the gravel range...
EDIT: and just remembered that one of my sons has a Scott Flow Trail zip jersey, exactly as you asked for....
Doesn't fulfill the zip criteria, but decathlon do a few 'fitted' AM jerseys, like downhill pajamas but not sized for a 661 pressure suit underneath.
Otherwise just size up? I've ever felt the elastic/gripper detracted anything.
Rear pockets on baggy fit jerseys are a PITA though, I've got an old Pearl Izumi MTB top that's (barely, it's old) elasticated and lacks gripper, and they keep trying to slide round. So that's enough of a reason to keep the gripper.
If you want to pay the Rapha levy
https://www.rapha.cc/gb/en/shop/mens-explore-zip-neck-technical-t-shirt/product/AJX01XXOKG