My Google Nexus 7 did same on one OS update. A reset helped. In other tablets I had to forget all old networks than add the network back in.
As to that guranteed fix, I guess everyone wants that.
Hi, I have a samsung tab 3 which I have had for about a year. All was well until it upgraded to android 4.4.2. Now, everytime it is switched off I have to manually log back into my home wifi which is irksome to say the least. Samsung suggested that it might be a router problem however we have 4 other devices that connect to the router, 3 of these are samsung devices that have no such issues. Samsung have suggested a factory reset also which I am reluctant to do unless it is a guaranteed fix. If anyone else has had this issue and resolved it or if anybody has ideas or suggestions, I would love to know.