I'll cut through all of it and suggest you go with what works and re-encode as required or try other servers. Tversity and others are often noted.
Sorry if you feel shortchanged but DLNA seems to be a committee affair. Features appear to have died in committee.
I have a Samsung 6500 BD player. I am using DLNA server (serviio) to pull movies off my network PC. I used to be able to ffw/rwd movies or go to tools and select a start point. After to latest update for my Samsung BD player, this option is not there anymore. So if for any reason the wireless connection gets interrupted during a movie, you have to start from the beginning again (ANNOYING!!). I have tried two formats mpg and vob. Anyone have any suggestions?