Fairlight bounce phase issues

I have a bunch of old 35mm films scanned 4K and converted to 25fps. I made a pitch down and normalized the dual-mono clips to R128. I bounced the tracks to file from fairlight page. Before the bounce everything sounded OK. So far 6 of 9 films were OK. 3 of them had serious phase problems. To be more exact, the audio wasn`t 100% out of phase, sounded more like those stupid pseudo-stereo 70`s things. Has anyone encountered this?

Were they matrix-encoded cinema mixes? Dolby Stereo / Dolby Surround? Or mono and you created dual-mono clips?

Detail your process. You'd need to ensure whichever pitch shift you use is phase-coherent on a stereo mix. I don't know that I'd rely on the built-in for this.