For the class of examples in Section 5 of the article in question, the proof of finite generation of cohomology is incomplete. We give here a proof of existence of a polynomial subalgebra needed there. The rest of the proof of finite generation given by the authors then applies.
"Correction to the article Finite generation of the cohomology of some skew group algebras." Algebra Number Theory 12 (2) 491 - 492, 2018. https://doi.org/10.2140/ant.2018.12.491