Slow fetch to data grid in 12.8


This is in my newly installed Toad (64 bit), under Win7 Pro.

When I execute a query (ctrl+Enter) I immediately get “Row 1 of 500 fetched so far”.
I also get one green square in the bottom, right corner and after some 8-9 seconds the result is show in the data grid.
It doesn’t matter if I change the query to give just a single row back, the actual fetch still takes way too long (8-9 secs).
After the fetch I get some “42 msecs” in the lower left…

Running the same query in my old Toad ( using the same connection, the result is shown at once (both single row and thousands of rows).
Both Toad versions use the same sql*net client, Instant Client

Is there some setting that could cause these slow fetches in 12.8?

Kind regards