Upon entering the caves or ruins the game will reset the season. A cave entrance will either be glitched or it won't be, if glitched it will always reset to the same randomly chosen season upon entering it. I find that roughly 4/5 of all entrances are glitched.
This glitch was never addressed on the wii u version, and it's still alive and well on the Nintendo Switch version. Klei can you please address this
enter the caves or enter the ruins