In Tahoe 26.0.1, my dock occasionally disappears even though settings show it's to be on permanently. I am able to get it to show by turning on "hide and show the dock" and then turning it off again in settings.
Mac mini, macOS 26.0
It is known macOS bug that is still not fixed Dock disappears randomly on macOS Tahoe 2… - Apple Community
Try to disable screen server as they suggested.
Bugs can be reported to Apple here:
Having said that, this issue has been frequently reported here and hopefully will be addressed in the 26.1 update due out very soon.
Dock disappears in Tahoe 26.0.1
