How do you have WL and WD configured to read data from VVP? Are you using virtual serial ports or network (TCP/IP) ports? Yes, both WD and WL are set to use TCP/IP ports 5511/5512
Does WL close its Weather Bulletin window? When data connection is lost, then the bulletin disappears. I now have disabled the bulletin and left WL running, it will only download data once an hour.
Does VVP have anything in its log (View → Activity Log). There are errors, but i will need to get these once the error happens again, (which may not happen due to what i have done above)
When you restart VVP, does it spend a few moments fetching the archive log (extra window shows progress), or does it start up right away? When i restart VVP, it gathers archieved data yes, it knows data is not up to date.