There are two links in a control panel on the left hand menu section. Link 2 is clear to see, but Link 1 is above it and hidden by the top menu section.
It was fine when I created it, but when I left the page to create a new form and then came back, it was as you see it below. You can just make out the dotted curvature of the link outline in this screenshot :
edit - if I double click the portion I can see of Link 1, then it resets itself properly and the links are both showing as they should do in the designer.
A fix for this issue is on its way! But it will only affect new M3 apps. Once the fix is live, I’ll update this thread, and you’ll be able to copy the standard-page.html from a new M3 app into your existing one to fix the issue.
I think it’s because it’s in Bug Reports, but I’ve never realized that before! I just changed the title of the post to reflect that the bug has been fixed.