+1 to this issue about to go back to apple,between this issue and the speaker phone issue, this phone is a steaming pile of **bleep** and holds up to Android phones being garbage again....
SAMSUNG FIX YOUR **bleep**!
I have a Similar Issue My S8+ will connect to Wifi everywhere but my home I have logged into 4 different Persoanl Wifi Networks not to mention places like MCDonalds and Starbucks and Barnes and noble and places that have free Wifi . I can log into them all fine but I cant log into my home network I get the Internet is Unavailable. I have Tryed 3 modems (2 different models) from Spectrum. I have tuned off every possible setting on my phone Done 2 Factory reset cleared Cache. I took all security off my network . Nothing changed.
Same problem on my Galaxy S8+ with Sprint. Works fine everywhere except work wifi which has duel-band outputs, 2.4ghz and 5ghz. Tried everything I could without going into router settings which I don't have access to for now. Looking forward to it's fix.
I purchased my Samsung Galaxy S8+ on 7/9/17. WiFi everywhere worked perfectly. Then suddenly on 8/29/17, my phone disconnected from WiFi at work. It would try to connect, then a second later disconnect, and on and on. I checked with everyone else in the office and all their devices were not having issues with the WiFi at work. I took my phone and stood right next to the WiFi router and my phone disconnected even there, so I knew it wasn't a signal blockage in my office. I freaked out, googled the issue and came across this forum. Noticed that some work around fixes worked for one person, and didn't work for another person. Spoke to a tech at Verizon - he hadn't heard of the issue and had no solution for me, other than to call Samsung.
Here's the Good News:
Well after having issues all day on 8/29/17, 8/30/17 & 8/31/17 --- suddenly (like magic!) my phone connected to the work wifi on 9/1/17 and stayed connected all day and every day since then until just yesterday 9/13/17 when it disconnected all day. Today 9/14/17, it is connecting and staying connected.
Have had no wifi connectivity issues at home or anywhere else.
So.... at least for me, it seems to be a sporadic problem that will correct itself in time.
Feel free to email me if you have further questions at email@example.com
P.S. The IT guy at my work gave me this info regarding the WiFi at work:
The access point is a UAP-AC-PRO, it’s a full 802.11AC access point, that supports both 2.4 and 5GHz bands.