Both use Ubuntu LTS so they have the same packages
Zorin has a more sustainable model of modifying GNOME, so Wayland support, modern stuff etc. But it lacks behind in versions and still simply is a hacked GNOME with inconsistencies.
Mint with Cinnamon has buggy Wayland support, Apps that are often really nice but dont really change much. Cinnamon and the apps are not often used outside of Linux mint.
Both are buggy in some cases.
I would honestly recommend Fedora (or if you want stability as in “the bugs dont change”, Debian, Ubuntu LTS) with KDE Plasma or GNOME.
I use Fedora Kinoite myself, it is modern but the base model is soooo much better for stability than the traditional distros. I use most my apps as Flatpaks, QGis and RStudio through distrobox. All apps apart from QGis are using Wayland.
It is really really good and I hopped a lot.
I do not recomment Mint or Zorin. Same as with ElementaryOS, or stuff involvinf XFCE, Mate, Budgie, LXDE/LXQt.