Odroid C2 4k doesn't display 4:3 as normal

I’ve got my Odroid C2 resolution set to 4k and the display 4:3 videos set to normal, but whenever I try to watch a tv show with a 4:3 ratio it is always zoomed in.

I originally thought this was a problem with the tv as the Aspect Ratio of my Hisense tv is locked to 16:9 when receiving a 4k input but I realised this is probably not the case as the play bar & info box display as normal during playback. I think the Odroid is choosing to zoom the 4:3 images overriding the setting in the preferences, cycling through the OpenPHT picture settings during playback does not make things any better & the picture completely disappears if I choose View Mode - Original.

I’m running OpenPHT 1.6.2.123

Any ideas?