Whenever I reinstall the server (which is a rented dedicated server), I backup a copy of the serveradmin.xml and serverconfig.xml as well as any xml that I’ve modified. Then I wipe all files including any saves, perform an install then delete the newly generated versions of the xml’s I’ve backed up and then upload the backed up xmls. If I’m doing this because of a new version update, I go over the new and backed up xmls looking for any changes. In your case, I’d do exactly the same thing, compare the backup to the new generated xml to be sure there are no syntax errors. If you are using a separate computer in your house to run the dedicated, I’d recommend uninstalling and cleaning your folders as explained in by clicking on the blue banner at the top of the forum.
I honestly don’t know if this will help in your case because I’m really not sure why this is happening in the first place. This could be a Windows issue, software issue, internet issue etc. instead of a 7 Days issue but I don’t know what else to advise. If you do this clean reinstall and you still see the disconnects, at least you’ll have ruled out 7 Days as the cause and will then move on to other possibilities. Let us know if it works or not.