"The outgroup was set to include the taxa Seymouria, Limnoscelis, and Orobates."

I just checked if that's responsible for your finding of synapsid paraphyly. It's not. Without designating an outgroup, so that PAUP* 4.0a166 uses the first OTU in the list (Seymouria), I get exactly the same results as you.

...all Latin -men words are neuter: foramen intermandibulare orale, caudale.

Automatically corrected by ICZN Article 34.2: "The ending of a Latin or latinized adjectival or participial species-group name must agree in gender with the generic name with which it is at any time combined [Art. 31.2]; if the gender ending is incorrect it must be changed accordingly (the author and date of the name remain unchanged [Art. 50.3.2])." https://code.iczn.org/formation-and-treatment-o...