I have noticed the same problem on three different projects.
I started each with the single tier tab strip navigation template.
When I click on a tab and the window opens, then I click on an adjacent tab, nothing happens. I have to click on a tab at least two “spots” away from the presently selected tab and then I can go back to the one I wanted to open. This seems to be intermittent. It may work well at times where I can click on each tab in succession and then for a period of time, I have to skip one and then go back.
I thought it might have to do with opening a pop-up from a separate button on one of the pages, but sometimes it occurs right after starting the project before I have opened any pop-ups.
Other times I have no issues. Like right now…it’s working perfectly…
I have toyed with the text padding and intertab spacing and it didn’t seem to help.
Has anyone else seen this?