Early closure of zoom meeting

check whether the meeting has a time limit based on your Zoom plan or account type. Also check if the meeting was ended by the host or another participant.

This is almost certainly the 40-minute limit on the free plan. The scheduled duration in your meeting settings doesn't override that, so any meeting with 3 or more people ends at 40 minutes regardless of what you set it to.

Two-person meetings aren't affected, so if it's just you and one other person it should run the full hour. Otherwise the fix is to upgrade the host's plan, or just restart the meeting when it cuts off and rejoin.