Mine doesn't want to recognize my 5ghz and wants to keep switching to 2.4ghz
Known issue, will be fixed in 8.1.1
Lots of funky stuff going on with 8.1
1. It keeps saying my 5 GHz wifi password is incorrect even though I KNOW it's correct. I changed my wifi password and then the iPhone accepts it.
2. Random connection freezing on 5 GHz.
3. Eventual slow wifi connection which requires me switching wifi off and on.
4. 2.4 GHz seems to work fine but max speed is slow.
2.4 max speed 40mbit down 5 ghz when working tops out at 120 mbit