A while back, all my saves were called "unknown" even in areas that had in the past worked such as the oak tree. Now, however, there is an issue that has affected all my saves, even ones extending all the back to why they were working. Now, items in my inventory are replaced and are always the same item. My crow crossbow was replaced with a sprig bow, and spider chest and leg armor (that I had put on maybe 60+ saves ago) is equipped. It seems as if the game merged all the inventories I had in the past together. Additionally, and even more worrying as this stops me from progressing, every time I load in a save, no matter what save, I load into my base, even if I am elsewhere. I am no developer but I suspect the game was corrupted somehow and has confused time tags as I always spawn with the same inventory in the same location, no matter the state of my save.
Edit: It also reset all my mutations to a past point, though all objects in the world remain the same including buildings and contents of chests. I lost a lot of progress so if anyone has encountered this or has a fix, it would be appreciated.