Ammonia smell after dealership repair - no exhaust or adblue leaks apparent

2015 VW Passat 2.0 CR TDI 110,000 mi

I'm getting whiffs of ammonia while driving. This wasn't apparent prior to the dealership repairing the leaking adblue injector and a warranty service to the EGR system.

Both the dealership and Indy shop have looked and can't find any exhaust leaks nor crystalization from adblue leaks.

Where to look next?