Lewmar opening ports
Am not familiar with the Lewmar port, but most ports have adjustments to compensate for gasket compression etc. that might lead to leaks.
Look for some way to tighten the hinges at the top of the port i.e reduce the clearance between the window and the gasket, and a way to increase the compression of the latch mechanism which will do te same thing. Both adjustments will allow you to make a tighter seal between the port window/gasket and frame which will usually stop any leaks.