I’m having the same issue. Working and checking my site on what is going on fro many hours now.
My test query sometimes returns results but most of the time comes back with error 404.
I have also sent a ticket to support. But they will probably tell me again that there is no support for code and will point back to this forum to post the issue (which I already did)
It looks like a general problem, so hopefully Wix will address this with the highest priority.