As I was in a meeting on Zoom, the meeting unexpectedly ended after about 45 minutes.

As I was in a meeting on Zoom, the meeting unexpectedly ended after about 45 minutes. Shouldn’t the meeting duration be unlimited for one-on-one lessons with only one student?

Even if you only have the basic, free account on Zoom, that should allow meetings of unlimited duration provided the meeting is with only one student at a time, namely two participants only are in the meeting. What you have experienced is most likely due to the fact that you or the student have logged in with more than one device. Even if the extra devices have been logged off after the meeting has started, Zoom still considers the meeting as a meeting with more than two participants since each device is counted as one participant, thereby limiting the duration of the meeting to 45 minutes.

After Zoom has ended the meeting you may just start a new meeting to finish your lesson. In order to avoid this problem just let your student know that he should log on with one device only. Note that if more devices are logged in simultaneously, that should appear on the participant’s list.