Must restart to have Dock appear in Catalina

Try starting the Mac in save mode once. You can do that by walking through the following steps:

1) Turn off the Mac

2) Turn it on like you normally do, but:

3) After 2 seconds press and hold the Shift key untill the login screen appears

4) Sign in with your password. You might have to do this multiple times. This is normal behaviour in save mode.

5) Once booted, check if the dock is visible. It can be a little laggy, but that’s a save mode thing.

6) Whatever the outcome of step 5 is: turn the Mac off again

7) When it’s turned off wait 10 seconds and start your Mac like always

Fixed it or not? Let me know!

I’m not sure what more you can do to fix it. I think waiting for OS 10.15.1 is your only option for now, unless you want to reinstall everything. I also have this issue with voice memo sync, which is probably also going to fix itself in the next minor update (I hope) https://discussions.apple.com/thread/250719736

I had this exact thing too. After restaring once it's working fine forever (untill now). But.. What exactly is your question? :) Or is it more like a message/warning to other people?

Oh I thought you already did fix it by restarting. Is the problem returning? Do you have any external screens connected? You should disconnect them before and during reboot.

How often did you have to restart it untill now?

And what exact type of Mac do you have?

Hmm. Okay, so you are restarting the Mac, it works for a while and then what happens next? I mean: at what point it’s not working anymore?