I don't think the problem is just with platesolving. Even I cannot see many stars in the image. The camera is otherwise in focus because I use a bahtinov mask when focusing on a bright star.
I think it is a combination of tiny fov and light pollution around where I am. My neighbor has LED lights on his porch, and I am near a big city. The thing is that with my lower power refractor or even guide scope, this was never a problem.
I am using player one Neptune c as my camera, which is a 178mc sensor. No binning. I start with 1 s exposure. I tried 5 seconds or even 10 seconds and the image just gets whiter and white, making it even more difficult to detect stars.