Sometimes the site gets overloaded and has issues. Try again later.

In Opera though, you can goto the URL opera://settings/content/all, type opera.com in the search field and click "Deleted displayed content". Then, repeat for gx.me.

Then, goto the URL opera://settings/clearBrowserData and clear "cached images and files" for all time.

If you're using Opera's built-in VPN, try with it off when on the the store.gx.me site. You can also test with all your extensions and mods disabled to see if one of them is causing issues with the site.