Several years back, I went backpacking in Guadalupe Mtns NP late in the fall.
First night, I woke up every half hour or so when I turned over.
Second night, I woke up two or three times.
Third night, I slept right through, 12 hours worth.
So I think maybe part of it is just getting used to it. Switching back and forth every night may have worked against you.
I had a similar experience backpacking when I melted my air mattress inadvertantly. The first night I awoke every 10 min all night, After that I slept soundly with only a ground cloth and sleeping bag for the next 8 weeks: of course it was 38 years ago...