Why isn't screen mirroring to Miracast working on my Galaxy s4 anymore?

[rlakritz]

I have have been using screen mirroring to connect my Galaxy s4 to my car's Blaupunkt New York multimedia system. It recently stopped working. It goes all the way through the connection cycle and then screen mirroring turns itself off and I see the following message on the screen in my car: WiFi Direct Succeed, Wait IP... This makes me think that the fault lies with the cell phone.
I recently upgraded my Android version to 4.4.2 and also upgrade to Knox 2. I don't remember if screen mirroring only stopped working after one or both of the upgrades. Could this be the problem? If so, how do I downgrade so that screen mirroring will work again?

 

[Rukbat]

Since the phone isn't going to supply an IP address (unless you're running a hotspot app), I'd say the problem is with the Blaupunkt. It could have recently received an update, making it not work unless there's a DHCP server (a router, which includes a hotspot app, includes a DHCP server) around somewhere, handing out IP addresses. A cellphone doesn't do that - it's a DHCP client (it gets an IP address from a DHCP server) not a DHCP server. (Running a hotspot or tethering app adds a DHCP server, among other things.) So the Blaupunkt is waiting for an IP address from ... what? Not from your phone, because it won't be getting one.

 

[rlakritz]

Thanks for the explanation. I read somewhere on line that people were having problems with this because of proprietary Samsung Allshare Cast being the only way to screen mirror. I believe this was a result of the 4.4 upgrade so people want to go back to 4.3. Do you think it is possible that the 4.4 upgrade prevents connection to Miracast devices? Is there a way to go back to 4.3?