Hi dave,
Really strange - but that should not be the problem.
Tried the query using psql - and of course it's returning data.
May be you should add an info about returned data in the debug log? something like "77 lines received"
First i'll use a network sniffer (wireshark) to see the answer sent to the client.
Next i'll install pgadmin4 from source (no big problem for me but using packets for such a tool is much easier)
thank's for your patience
Walter