This is probably already posted a million times in other threads, but...there's a lot of posts about problems finding matches or getting kicked out of games. I wanted to share my experience with this issue.
Last night I fired up For Honor on PS4, and was immediately frustrated when I could not find a match in ANY game type. I noticed that the NAT symbol was red, and it said "NAT type: Strict" in the loading screen while trying to find a match. I logged into my router admin console, and UPnP was not enabled. I turned it on and restarted my PS4. After that, I was able to join games almost instantly.