Joshua,
The board goes into its executive sessions by the president simply saying that they are, with no motion made or vote taken, then he dismisses all non-director members from the meeting.
When the meetings were held by Zoom, non-directors were disconnected. We non-directors did not know when the executive session ended and when and if the rest of the meeting continued. If we tried to "re-enter" Zoom, members were selectively re-connected or ignored.
When the meetings were in-person, the board secretary would invite all members still in the vicinity and let us know that the executive session was over.