Ok, i got home and tried the settings that madeinbeats suggested earlier and so far so good
I tried my Wii U when i got in but was getting the same disconnect problems. I updated the advanced settings (only the the IP address in DMZ needed entering all the other settings were correct) and rebooted the SH and all seems fine. No disconnects from Miiverse, eShop, or the street map app. Fingers crossed it stays this way. Thanks for all the help, suggestions i received in a short space of time.
I may celebrate by getting Lego City Undercover