Exactly opposite. Accessing Euro-zone in 1999 has stabilised Spain's inflation at around 2-4%, before getting into Euro it was wild.

https://tradingeconomics.com/spain/inflation-cpi

From 1997 until 2021 it was at a stable 2-4%. 1985-1995 it was 5%-10%, and 1965-1985 it was 10-20%.

Also, if you compare inflation of say Czech Republic, Slovakia, Poland, Estonia and Estonia (or any other comparable countries), you will have a difficult time spotting which ones of them have Euro and when it was adopted.