As of 06/17/22:
Every server, every time. Without fail, either "no session available. Please try again later." or "Cannot connect to Activision Matchmaking (Error code 5)"
Steam install, with mods torrented into the base game folder. Torrented mods, then dragged and dropped into their respective folders and replaced duplicates.
Is this a problem on my end or plutonium? Either way, it's annoying, I cannot play at all.
Edit: Where are the mod/dev replies in this thread?