Does any part of the problem tab control cross or touch the boundary between header and body? (That often leads to problems with FileMaker tab controls.)
No. I moved it to different locations in the header.
Actually, I discovered the issue is not that the tabs aren't changing. The tabs are working as scripted. The issue is the elements on the tabs are not showing up when the tab control is in the header in IWP.
Thanks in advance for any help.