I have a samsung range and washer. Both have been connected to smart things. Every once in a while I have to reconnect the washer. This time Nothing works!
It says it has been factory reset and I have to add it again.
I have tried removing it from my phone and from my wifi. I tried connecting using the 2.5 ghz, i have unplugged the washer. Password is correct. It just keeps saying incorrect password. No problem at all with my range.
This is really frustrating and no reason Why it should keep disconnecting after working.
Make sure that WPA2 or WPA2/WPA3 is enabled in your router settings. WPA3 only won’t work.
WPA2 is connected
I had the exactly same issue. I’ve tried all as Kal1 did and checked WPA2 connection as well. I’ve even tried the network reset in washer as the other Samsung community recommended, which was not working either. The solution of mine was just refreshing the WIFI router itself (I’m using spectrum, btw) 
I couldn’t even think of it since the other 25 devices including Samsung dryer were working at that time without any problem. I still don’t understand why only washer had this issue, but refreshing the router worked for me!!!