auto-hide dock does not show up

Since I upgraded to 21.04, my auto-hide dock (at the left of the screen) remains hidden until I switch its position to the right and back to the left. After that it works as expected (i.e. it appears when the mouse goes to the left edge of the screen).

EDIT after @vanadium's comment:

Normally the auto-hidden dock should become visible in its chosen position (left, below or right) when the mouse cursor comes to this edge of the screen. But for me, after starting up the computer and logging in, this does not work. The dock does not appear.

I have to change anything in the dock settings (e.g. change the location or switching the auto-hide feature off and on) to make it work correctly for the rest of the session.

PS: Today it worked from the beginning without any intervention. A mysterious case of self-healing?

PPS (one day after the PS): It happened again today. Perhaps a question of timing during startup? How can I delay the start of the dock?

This is my version of this issue.

When the application's window is "full screen", there seems to be a "speed-related" issue detecting that the cursor is against the screen edge where the "dock" is located. If the cursor icon meets the screen edge slowly, the dock does not appear. If the cursor icon is "crashed" into the screen edge, the dock will appear. However, when the dock appears, it may be: (1) "bouncing" and will disappear when the cursor is moved in any meaningful way; or (2) the dock will be stable and can be used as desired. The author of this feature may have had two objectives. First, if the cursor icon accidentally touches the screen edge, the author wanted the dock to remain hidden. For me, this is a good feature. I applaud the effort. Second, if the cursor icon is "slammed into" the screen edge in a meaningful way, the user is indicating the dock should appear. This result seems to occur - most of the time. Appearing every time would be even better. However, the bouncing dock has me getting sea sick. There must be confusion inside the algorithm deciding if the "cursor" meets the "screen edge" slowly or quickly.

A not too scientific observation: Success making the dock appear is better if the cursor icon impacts the "screen edge/dock-area" where there are no dock icons.