[1.1.107] Desync during map load

[cored912]

we seem to be able to play for a few minutes and then the map tries to download and the client desyncs from the host. seems to happen no matter who the host is.
what we have tried:
verifying game files
no mods
remove autosaves
allowing firewall settings

tried to search a good bit for a solution but most issues seem to revolve around mods and we are both playing vanilla. any advice would be appreciated. thanks.