I have already tried testing with different applications open, near and not near the launcher, to see if perhaps an application is interfering with the launcher, but no application causes the problem to happen reproducibly, and sometimes it happens with no applications open at all.
During a 2-hour period of use, I typically have 1-3 times when I can't get the launcher to unhide.
Trying to type in the Alt-F2 window (and/or the window you get by clicking the Ubuntu button in the top-left corner) is successful about 70% of the time and fails about 30% of the time. Also does not seem to be affected by which applications are open.
The drop-down arrow in the window you get by clicking the Ubuntu button appears less than 10% of the time, and is missing the other 90% of the time.
Both problems are intermittent, unfortunately.
I have already tried testing with different applications open, near and not near the launcher, to see if perhaps an application is interfering with the launcher, but no application causes the problem to happen reproducibly, and sometimes it happens with no applications open at all.
During a 2-hour period of use, I typically have 1-3 times when I can't get the launcher to unhide.
Trying to type in the Alt-F2 window (and/or the window you get by clicking the Ubuntu button in the top-left corner) is successful about 70% of the time and fails about 30% of the time. Also does not seem to be affected by which applications are open.
The drop-down arrow in the window you get by clicking the Ubuntu button appears less than 10% of the time, and is missing the other 90% of the time.