2
  1. Pin a tab
  2. Click on the normal tab to it's right (the left-most full tab)

You will see on the left-hand side of the selected tab that its shadowing is messed up and there's no rounded edge above the one on its left:
https://ibb.co/t8wH1Lf

Contrast this with the same tab, but pinned, where you can see the correct design implementation:
https://ibb.co/FbG2sQ7

There were tangental bugs reported and fixed:
https://orionfeedback.org/d/3400-rounded-tab-css-ui-glitch-when-next-to-pinned-tabs/13
https://orionfeedback.org/d/4373-rounded-tab-ui-glitch-when-next-to-pinned-tabs

However, they didn't spot or touch upon this particular issue.

    I think this is fixed in the RC already so will mark it as such, feel free to reopen after the release.

      5 days later

      Received the update yesterday and I can confirm that it's fixed. Thank you very much for responding so quickly!

      I personally like the rounded tabs, but I have noticed a few more quirks:
      https://orionfeedback.org/d/5114-rounded-last-tab-ui-glitch-when-dragging
      https://orionfeedback.org/d/5115-hover-is-cut-off-when-hovering-next-to-the-active-tab
      https://orionfeedback.org/d/5116-separator-remains-between-pinned-and-normal-tabs

      No one is typing