I am experiencing a similar problem. Ordered top of the line 6" thick extra dense foam, but with gaps between the panels heat leaks out bad.
Thick cover doesn't help if heat leaks out the sides. They also made the cover with Velcro to hold the panels together instead of a seam. I've never heard of a cover without a seam, but that is what they sent me. You cannot fold the cover on top of itself without ripping the Velcro loose which is a pain having to reconnect it.
I had several detailed conversations and emailed picture of my lift to be sure they knew what I needed. They agreed to make another outer cover with a seam, but I have not received it yet. I am not holding my breath, but hopefully they come through. They refuse to address my complaint about heat leaking out.
Paid $550 and am regretting it so far. I will update my review with a positive responce if they address these issues but I have a bad feeling.
Reviewer is in unhappy mood. This person stated that there is a room for improvement of communication. Please immediately contact the author of this review to discuss not as described of cover valet hot tub cover. Hot Tub Works needs to "address my heat loss issue" according to poster's claims.