Hi Peter,
I started out using the LNAL port, too, but soon found that the LNAH port worked better for some reason on the FM band. Just from what I can see on your setup in GQRX, everything looks right. I would strongly suggest you use the LNAH port and make sure you’re on the first set of ports since GQRX (for now) isn’t capable of looking at the second set of ports (that I’m aware of - all that is in the list is one set defaulting to the first set of ports on the board). Also, ensure you’re using a good antenna, too - I’m banking on it that you are. Also, I know that you mentioned that you’re using various sample rates, but I found 1.5Mbps worked well for the FM band - so make sure you are loading it (even though the form seems to disregard it everytime I’ve ever checked on it again).
Try those suggestions and let us know if that works (or doesn’t).
73 de Marty, KN0CK