We're unable to search for a property by value (link here). We just get "NotFound" returned.
Have tried a combination of:
Hostnames, with wildcard, without, propertyname with wildcard, without, complete names or not. edgehostnames with wildcard, without, full and partial names.
And a bunch of other things around JSON body, incorrect URLs, method etc.
If someone has an example of a query that worked for you, that would be great.