Why does focus' moon icon in my Mac menubar turn yellow sometimes?

Thanks @dialabrain. 

• I did check "System Preferences > Notifications & Focus". 
• There are no custom, automatic, scheduled or shared settings.

• I was using cmd-shift-4 to take the screenshots for my original post.
• Whilst doing that I noticed that it correlated with the moon turning yellow.

• I've made a video to show you the odd behaviour - 

• There's even an instance (around the 40 sec mark) where only half of the crescent moon turns yellow.

• You can also see my Focus prefs in the video, with no custom settings.

• I booted in Safe Mode. The problem didn't occur whilst in Safe Mode. I restarted in Normal Mode and the problem hasn't occurred since. Maybe Safe mode's cache cleaning etc. resolved it. It's hard to be certain yet because it was only an intermittent issue. Fingers crossed!

Thank you!

[Link Edited by Moderator]

Sadly it's still happening.

I think the logical way forward is the instructions beginning "If the issue returns after leaving safe mode" on the page that you sent me to.

I accept it's the only way to narrow down or eliminate potential causes. However, it also sounds tedious and not guaranteed to work. I'm not sure if the pain of the issue warrants the pain of these troubleshooting steps. We'll see.

The moderator bot scrapped my Dropbox link but I don't think the video will help at this stage anyway. Please tell me if you disagree and I'll embed it via YouTube.

Thanks again for your help @dialabrain