I have had the same problem, especially with the bow hatch. In fact I ordered a second front hatch. I had to heat the wood with a small ceramic electric heater to soften the wood. This worked well for me. I was told you can use a hair dryer or the microwave oven. I would try heating the wood to make it more flexible. Good luck.

   I built this boat for my wife in 2018 and had the same issue.  Mine actually broke as I stitched it together.  I had to patch it with 4-once fiberglass cloth and epoxy.  I remember tightening things gradually all the way around to force it into place after the repair.