Hello. I have noticed, what Dude client may stop working and disconnects from server, if server does not have graphic image for network device.
I think for some reason, during Dude upgrade or reboot, file was missed from disk (on router). Because of that client unable to retrieve it from server and goes kaput. After I noticed which file missed, I reuploaded it and this problem was gone.
P.S. I am 99% sure in this solution. 