Pinned Top Site that becomes "unpinned"

After using Brave for many months now on my Windows 10 PC, in the past week I have had a problem with one of my pinned Top Sites on a new tab page (nbcnews.com) becoming mysteriously unpinned. This has happened twice now and neither instance was a case of me accidentally ticking the pin to release it. Rather, it’s been that the web site has disappeared entirely from the Top Sites selection when Brave is booted up at the start of a new session (and that alone is odd since you’d think that as often as I went to that site while pinned, it would remain a Top Site even if unpinned).

[ADDED LATER] And then it magically re-appears, in the same place it once occupied and still with the pin activated. What is going on here?

I have seen the same problem with the latest version of Brave under OS X.

I am having the same issue. Except when my site appears again it is unpinned. I have repinned the same site at least 1/2 a dozen times. Why is it being unpinned?!?!?