thank you @meself2

but still the word used here is should, not must, so I guess this is probably why my wife got it renewed every 2 years previously?

Hi, I was a previously critical skill visa holder and now I am in Stamp 4 which I need to renew every 2 years. My wife joined me at 2019 as Joint Spouse, and she had 2 Renewals with Stamp 1G already when we were in Dublin, and her expiration date is always the same as me. i.e. She also renews every ...