Samsung S7 unable to connect to my home WiFi only (D Link DI 524 router).

[AC Question]

My S7 works fine on my office WiFi or free WiFi outside. Plus, my S5 also works fine on same home WiFi (ie same router). How's come just my S7 having problem.

I have tried factory reset. Sent my S7 back to Samsung for check, but problem still exist. Can I please get some help?

Thanks.