I have a strange problem with the Software store:
When i try to open it, the Software store starts in the background but no window is rendered.
The taskbar display the store as "opened" but hovering it display nothing.
(my system is in French)
I have tried to open it with the terminal
gnome-software
I have also tried to reinstall it and clear the cache
I suspect you are correct. On a recent install of Zorin 17.1r2, I wanted to install Synaptic Package Manager. The default desktop was in use (Wayland) and while Software showed up, it did not come back with Synaptic Package Manager, I had to login on xorg before it would show. Another area you should look at is your software sources. If this is set to your country server it needs changing to Main Server. Just to add I removed Zorin Desktop/Gnome and replaced it with Plasma and Enlightenment.
When You have ''open'' Gnome Software - when it is in this Condition like You showing - open the System Monitor and search under Processes for gnome-software and end the Process. Then You should see that it isn't active. Then click again on the Gnome Software Icon.
Another Thing: You have used the Link at the Side of the Start Menu. Did You tried the Icon in the Software List on the left Side?