Hi,
In the latest development build I have noticed that panning a WMS layer is taking a very long time (minutes in some cases) and the network transfers almost 30MB over this time. Zooming does not have any problems and takes less than a second with network traffic around 600KB.
Development builds 5.5.110 and 5.5.117 have this issue.
Version 4.0 does not have this issue, takes only seconds to pan and transfers 600KB network traffic.
Damian