I think it might not be the same case, as the filter function on thehive works normally, you can see in below sample, that thehive title filter works with the exact match of the title. but if go within the n8n, it will failed to retrieve the info.
That sounds like the exact same issue that was previously reported, A search in The Hive works but the exact match from n8n no longer works because of an API change. A partial match in theory should work but only if it is lowercase.
I tried to contact the support the Thehive, they suppose it is not thehive problem. the developer claimed their checked in 4.1.20, absolute search on description or title works, the UI uses the API, there’s no way can have different results if the call is the same. they suppose there’s some parameter or expression problem on n8n called. can you further look at this?