Long autumns causing irregular spawns

I change my world settings pretty regularly, and for the most part there aren't any issues. However, the long autumns in particular seem to cause issues.

When I created my world, autumns were set to regular length, but from my second year on, I changed them to long. 

Last in game year, I heard Bearger warning sounds on at least four separate occasions. After a short time, the sounds would stop, but no Bearger would spawn. I verified this with the c_countprefabs command each time, and it always printed 0.

The next winter, the sounds had stopped. By about mid winter, Bearger randomly appeared hibernating just south of my base.

Today in my world is day 372, about a year after the Bearger incident. I haven't been in autumn for very long, and there is no snow on the ground, but I am starting to freeze as if winter is coming despite having long autumns. Deerclops also spawned, so it's possible I just got an early winter spawn and autumn wasn't actually shorter than normal. During the fight, however, Bearger spawned hibernating again. I had no warning sounds for the entirety of autumn this year.

I also haven't found any no-eyed deer in this world, and c_countprefabs returned 0 every autumn as well. But that could just be that I didn't go near the Deciduous Forests or Mosaic Biome around the right time to have them spawn, if that is normally a requirement.