Thanks for your reply.
This issue is independent of data set, but one on which this occurs is the Diabetes.jmp data set (attached) from the JMP sample data folder. They're currently using JMP PRO 17.2 on recently purchased Macs with OS Sonoma 14, but it also occurred with JMP 16 and 17 with this same hardware/OS setup.
I've been using JMP in this intro class since 2018 with only occasional minor glitches on Macs. This is the first non-trivial issue I've encountered.