glue/adhesive for wood and lexan?

[Wheels]

I have a small lexan piece cut out for my close out panels at the sight gauge opening in the cockpit.

I tried to glue it to the outside window frame and the adhesive simply would not hold it. first I tried pure silicone adhesive, then I tried a two part epoxy. Is the small surface area of the fabric covered part killling the adhesion? I didn't want to screw it into the wood, the old ones were glued in, heck, it looked like "Elmers."