So, uh… We have the same thermostat at my job. It’s not great. You can’t just tell it what temperature you want the room to be, you actually have to tell it if you want it to heat or cool to that temperature.
Yours is set set to 65, but if you look to the left of the current temp, it says “heat.” Someone likely forgot to change that when the weather warmed up. IIRC, one of the three unlabeled middle buttons will fix that.
You mentioned that the house is a century old - I’m assuming it was built as a single dwelling, and subdivided later.
If that’s the case, my best guess is that the basement had a problem with flooding during bad weather, so they busted holes in existing drainage pipes to allow water to drain from the basement. The leaky walls were most likely sealed when it was converted to an apartment, but… Well, drains drains are great until they back up - I would be concerned about water coming up through them in particularly bad weather.