Of the two and with the symptoms you describe I strongly favour fix first sequence in processing. A totally dead but new developer is possible but about as likely as discovering hens' teeth.
Sorry but many of us, including me, have been there once.
I am sure that B&H and then Rollei will want to know about this. It may not help you other than in terms of compensation but it should help others. If Rollei has produced totally defective developer then in the quantities it is made you can be sure that it wasn't just your container. Maybe 100's of others are experiencing the same issue or are about to ruin their films in the same way.
By the way I keep hens and will never feed them by hand again. Next time it is the lion tamer's chair when I go into the henhouse
Developer will likely not smell like ammonia unless fixer was poured into it. Think about this for a minute. How did fixer get into the developer, or developer get into the fixer, and how did that affect film developing?
"...the heart and mind are the true lens of the camera".
- Yousuf Karsh
"We are what we repeatedly do. Excellence, then, is not an act, but a habit".
- Aristotle
First, the MSDS indicates this is a Metol-Hydroquinone developer. Second, it does not makes sense to say Metol-only developers are prone to any kind of sudden death. The shelf life of a developer depends on the entire formula. Even packaging is an important variable.
I have no experience of this developer but it still seem incredible to me that a brand new developer is susceptible to a kind of sudden death that prevents even a trace of development.
I'd hope that Rollei will ask for the remains, if there are any, of the suspect developer and thoroughly test
If it is sudden death and the stuff is brand new this would put me off ever using it again.
If this was an Ilford developer Simon Galley would have men demanding it back in the middle of the night for immediate testing.