[2022] DLC not supported on Standalone Paradox V1 launcher

Do you really mean the v2 launcher? Or the v1 launcher, aka standalone Paradox client?  

The DLCs ought to show in launcher v1 (which BTW is really a client like Steam, not a launcher as such), but there have been issues in taht area it is true.

Did you really want to use that launcher instead of Steam?