Can someone tell me why Tidal MQA shows as 96Khz when using a non-MQA DAC?

Mine does the same. Never seen anything higher from Tidal Masters. I'm guessing that's their highest rate for the streaming content.

As I recall, if you are using the Chrome or Tidal app, that's what it should do.

I don't know of any way to pass the original MQA stream directly to an MQA enabled DAC.

I thought it might display 44.1 if you use a non MQA DAC.  

There are a couple of steps to the MQA > analog process.  If you don't have an MQA authorized DAC your streamer does the first unfold to 88.2 or 96Hz /24 bit  You need an MQA approved DAC to go higher than this.

Here is a link to the explanation:
http://www.mqa.co.uk/customer/how-it-works

Tidal does stream many albums at 24/192. 96 is not their limit.
However 24/96 will be the highest you will see on a non MQA dac, as it cannot complete the full MQA unfolding.

It will still sound mighty fine though!