You are not alone.
Recalling from college neuroscience classes and subsequent reading of research, the studies show the ordinary human sleep cycle when unrestrained adds about a half hour per day, so 24.5 hours is 'natural'. Long-term studies with all time cues carefully removed ended up with subjects on a ~50 hour sleep schedule, as in awake 36-38 hours and sleeping 12-14hrs.
This is also why it is easier to travel across time zones to the west than to the east.
I think I'm gonna try and find a study that had the 50 hour sleep cycles
It was a person free-running in a cave. Here's one article about it [0] to get you started, and here's another [1] of multiple 9-day studies showing the fairly immediate shift to 24.5 - 25 hour cycles (we're actually Martians?).
[0] https://howandwhys.com/michel-siffre-time-experiment-body-sl...
[1] https://www.researchgate.net/publication/339110740_Living_Wi...