Half-Life 2 Campaign?

This has been asked before but the mods that let me do this are outdated. Is there a way I can play Half-Life 2 levels online in Gmod with a friend, complete with level changers? At the moment the levels somewhat work but it doesn’t automatically switch levels. Is there a way to fix this?

Yes we are playing Syngery at the moment but we want to do more with it in Gmod.

Levels actually do change, both in MP and SP in sandbox. Although A LOT of stuff is broken with the maps, so it isn’t entirely playable, especially the episodes.

What are some of the things that are broken? I only know of a few.

I still haven’t played through all levels, but here’s the list I compiled so far: