From what I've seen on the forum lag seems to be common, but I haven't found a solution to fix the issue. When the user makes a selection on a drawing it is about a 2 second delay to actually select the objects in the drawing and then when they move they right click to move the object they are experiencing a 6 second delay. What has me baffled is that this is not affecting every user, it seems to be hit or miss when it happens. Devices are all identical on the hardware wise and software is identical on each machine.
Could be UPF related. Try workarounds UPF related, RestoreDefaults (one at a time) and check if the lag goes away.
Do also check if your graphics driver is updated to latest.