Jan Jansen doesn't interact with you? No Problem! Here is a fix:

[Buuh]

So I had this rare bug, when I declined to let Jan Jansen join me right away, I couln't interact with him later when I clicked on him. Which means I wasn't able to recruit him later.

Since I couldn't find a solution in the forums, I asked for help in the Beamdog Forums and a very nice and competent person, told me how to fix this problem. Now I want to share this fix here, in case somebody encounters the same bug.

First you need to open the console:

Press CTRL+SPACE (you will first have to enable the console in case you haven't already, there are many tutorials how to, so I won't explain this step here)

Next type this in console:

C:SetGlobal("TalkedToJan","LOCALS",1)

IMPORTANT:
As it is a local variable, you will need to hold the cursor over him when you press Enter for the value to be set.

You're done! Jan Jansen will talk to you again.