Personal hotspot doesn't work anymore in iOS 8.4
I upgraded from iOS 8.3 to 8.4, and now Personal Hotspot doesn't work anymore. It is enabled and should de discoverable over WIFI, but no device, including my MBA can find it. Over bluetooth it works, but the network speed is almost zero, whilst 4G on my phone is very fast.
Any ideas on how to resolve this?
iPhone 6 Plus, iOS 8.4, null