Ah that sucks there’s nothing worse for a homeowner than an issue you can’t solve because one of the things you need to solve the issue can’t be found lol.
Hopefully you find the snake and get the drain operational! I won’t say fixed because in old houses things are rarely fixed but they do become operational! Lol
It sure sucks, and it annoys the hell out of me. Though we're not homeowners, we rent this place, but our landlord sucks even more at maintenance. I will keep looking for the snake, (snakes can hide themselves very well), and hope to get the sink operational again. Indeed operational, very well said!