Downloaded a mod with Nexus Mods’ Vortex and was warned that it needed to be installed manually in stead. I did so and now Vortex simultaneously says that I never installed it via Vortex (correct) and that I enabled it in Vortex 54 years ago, 13 years prior to my birth (surprisingly not correct) 😄
Seems like it recognized the mod somehow being installed but, as it didn’t go through the normal process, it never set a proper date of installation. Instead it must have defaulted to 0, which in Unix time is the begin of the Epoch, in 1970.