Just now an update released, after the update wifi is not working in High bandwidth, but 2.4G band is working fine form my router.
The exact problem is when I connect in High bandwidth connection, it connects for some seconds and then it disconnects, it's going on in a loop. Then wifi connection scanning phase is hanging afterwards. Right now I have connected in 2.4G band, it's working fine.
Note: When I bought the phone in factory settings, faced the same issue. After the updates, it was fine. But after the version 17.0823.2009.99 , it's reverted and it's worse than before.