step 1: read the warranty supplement that came with the car when the emissions system was "fixed" circa 2017 by a VW dealer (I am assuming your car had the "fix", almost all were fixed and owners received $$ from VW to boot) and see if the warranty is still in effect. IF so, go straight to dealer.
step 2: If step 1 indicates the warranty is not in effect, you have two options:
A) take the car to a mechanic skilled in VW TDI diesels (not necessarily a dealer) and expect to spend a lot of dough doing some repairs to the emissions system, e.g., installing a new Diesel Particulate Filter, or other components, possibly thousands of dollars, and the car could be out of services for days, weeks or even longer. OR
B) consider tuning the car with Kerma tune.
https://kermatdi.com/
The cost information and installation instructions are found at their website. This will likely be a long-term solution for your emissions system woes, at least it was for me, as I was having a similar issue a year and a half ago.
CAVEAT - without knowing more about your car, maintenance history, miles, previous repairs, etc, it is hard to be more specific or perhaps send you in a different direction. But, in any case, start with STEP 1 above.
any ideas?
