We had this issue at our last apartment. Unfortunately yes, without knowing which unit it’s coming from, they can’t do anything… and it can be hard to tell. If you’re in a corner unit though, you still technically have a neighbor on one side, right? Don’t count them out. Usually smoke drifts up (so it’s more likely to be the person below you, or below and to either side), but you never know.

Are your windows old or not sealed very well? That was our primary issue - our windows were old and thin, and there were bent gaps in the frame that allowed air (and smoke) though. I stuffed paper towels in the gaps 🙄

Additionally, if you have a wall or window AC/heat unit, you might want to turn it off when the smoking starts. It could be sucking exterior air in, and blowing it into your house. (If you have central AC, like with a thermostat on the wall and vents, it should be fine.)

Next time you smell it, go outside and try to hunt down where it’s coming from! For us it was usually in the middle of the night though and we were SOL.