Mine works just fine on my PS4.
What did you burn? The ~7GB AVCHD or the ~18GB MKV? Did you burn it onto a DVD-R DL or BD-R? What software did you use? If you used the MKV, did you convert it to a BDMV folder first, or are you just playing an MKV file that's on a disc (which the PS4 definitely wouldn't support, but many Blu-Ray players would)?