Once in a while, pressing ⌘F within the note shows the top search bar, but doesn’t put the focus in the Search field, and loses it completely – typing doesn’t do anything. Sometimes you can briefly see the focus mounted properly, and then disappearing, so it might be some race condition.
Unfortunately, I don’t have a consistent repro. I do like ejecting individual notes as separate windows by double clicking on them first, and I often see ⌘F fail to focus in that context, but not sure if that’s related in any way.
I can confirm this is happening with me as well. I have several Keyboard Maestro macros that use ⌘F that have been randomly failing. This post helped me figure out this was the cause. It seems to happen randomly, so it’s difficult to reproduce. Maybe 20 percent of the time?