Samsung Note 5 Wifi connectivity problem. A JUNK?

All our devices have excellent wifi experience and internet activities but the Note 5!  We wipe off the cache partition already, deleted our wifi from the Note 5, turned off and on our router, well it worked for a bit but then it's back to the same wifi problem again.  My son is starting to believe that the Note 5 is a JUNK.  Can anyone please offer help on this issue?