Good luck with it. Judging from there being only 3 of us in this boat, the problem is either very specific to circumstances or others either don't load balance or use linux, mac or such. Perhaps I'll start up Ubuntu and give it a go..

Please post if you get anywhere or not as the case may be

Just had a breakthrough of sorts:
Our Lan topology looks something like

Internet
|
Draytek
|
Windows EBS Server
|
Switch
|
Workstations

When I connected to the router through wi-fi, rather than through the wired desktop connection which goes through the EBS server, it works consistently.

Interesting, if somewhat annoying!

My last post was only a little later than yours, so I guess I should type quicker!

Have now seen that 3.3.4 is available since June and the readme says

91. Fixed: A load balance bug.

but gives no further info. Have not tried it yet. Interestingly the Draytek Taiwan site describes how to set up a scheduled reboot, that's also not a part of 3.3.3

Regards

I'm avoiding 3.3.4 due to the issues detailed in a thread here. I've got the fear!