Dry Middle on infused plate

Just tested out a resin infused plate after a few wet lay versions I successfully made.

The only problem is I've got a dry centre section on the bottom surface so resin is getting all the way through to that part.

This is the second time this has happened but I took the first as me making a mistake.

The plate is around 5mm thick made with 3k and UD layers - no core.

Bag sealed up fine and no change on drop test. I infused slowly and had resin coming into the catchpot. I clamped off vacuum first and waited a few seconds before clamping off feed.

You'll hopefully see from the photo that I'm putting the spiral across the back edge and roughly half way down the other edge. Should I just have the it at the back to allow it to go through the lot? Or flip it to short edge so it's pulled through less width?

What am I doing wrong?

Thanks