Im having this problem now also. my switch has been working sence this summer and now i am having this same problem even when i host the game. Try changing your internet settings.
i got this from a post back in the summer i copied it and saved it on my notepad i hope it helps, here:
1. Start to setup an internet connection.
2. Pick Wired
3. This is where most people get the settings horribly wrong. Pick MANUAL! (Picking easy will waste precious time looking for your information after you flip the switch, while having already memorized will allow it to re-connect faster)
4. Enter your IP information (if you don't know your ip address then setup an easy configuration, then look at it from the internet information option)
5. Pick 10base-T Full dulplex as you ethernet type.
6. For anything that asks if you want to enable or disable, disable it.
7. Anything I didn't mention, leave it the way it is.
8. Test your connection to make you the new connection works.
9. You should now be set. Test it out by signing back in to PSN then flip the switch. If it doesn't say "ethernet cable disconnected" for a few seconds then you should be good. If it says it immediately then you have probably just done something in your construction of the actual switch. If this is the case, then you should probably start from scratch with a new ethernet cord.
you can use 10 half or full, i use full.