The F-35B has an auto-eject function which the other 2 models don't have. Something to do with being in hover mode. The jet flew 60 miles after the ejection before crashing in a field.
It really sounds like the auto-eject feature caused this since the jet flew on for that long before impacting what looked like rising terrain:

https://apnews.com/article/f35-crash...%20Subscribers