I am seeing this same issue...
I tried removing and then re-adding via the manage installation -> configure.
Even created new characters or took the default characters.
I do not see the DLC items but it says they are present.
I do have both the PC (GOG) version and the PS4 Version. So I expect in the PC (GOG) Version that I would have gotten the DLC items right away... like in the PS4 Version. I prefer the PC Version... do not like the PS4 controls for a TAC RPG of this type.
**BTW I actually paid $45 dollars combined for PC (GOG) and the PS4. Now I have been waiting for 3-4 years since this has been in development, but that is the rub.
**I had hopes that this would be more bug free since they extended the release and enlisted the support of Microsoft but it is the old inXile habit of not proper beta testing "the whole game". We will have to wait (again) for a "Director's Cut" before we get the game we wanted on Day 1; we should see a Director's cut a year from now. I think we are fortunate that they honored the multi-platform release since of the association with Microsoft; at least this is not an XBOX/Windows 10 Store exclusive.
**As for as beta testing goes... Square Enix is one of the companies that seem to do this better than most (there are probably other examples)... I have seen fewer than most patches for issues that come from their AAA/AA titles than other companies. I think Wasteland 3 would fall into the AA title category and for the next game should look for examples in the industry that do internal beta testing correctly. Throughout the industry it is common for the customer to be the beta tester... I wish that trend would reverse.