mqstout: Blues, fix this.
From what I've been told, at best, moderators can forward issues to other teams.
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About the issue, while there doesn't seem to be an obvious way to search for devs/publishers, I tried opening the direct links for some random devs and publishers from games' store pages and all seemed to work fine.
Alternatively, the script "GOG Games data grid view" still works and it lets you search for either devs or publishers:
https://github.com/ghorint2t/scripts/blob/master/goggamesdatagridview.user.js You can install the script with plugins like Violentmonkey.
And once you have the plugin installed, open
https://www.gog.com/games, wait for it to fully load and click the grid icon to the very right (it will be to the right of other two similar icons).