Welcome Simprob,
It sounds like docked apps don't open their windows when launched.
When this happens, do you notice a small dot under the apps before you click on them again in the dock? That should reflect that the app is indeed open.
If you haven't yet, let's test this further using safe mode: How to use safe mode on your Mac
Booting here is slow than normal. It will prevent some apps and processes from working. When you boot there, try launching a few apps to test it out.
Then isolate it further using other user on your Mac. If you don't already have another user, learn how to create an Administrator account using steps in: Set up users, guests, and groups on Mac Log out of your current user in the Apple menu > Log out. Then log in to the new user to see if the issue persists there.
Let us know the results of these steps.
Wishing you well, take care.