They may have been recorded in an H.264 standard or profile not supported by the DVD player. You will need to make sure your Sony player supports the H.264 profile and level you are using, and that your recording is compliant with the Sony's supported standards.
For example, the player may only support H.264 Main Profile Level 4.1 and a maximum of 3 B-frames, which limits you to 1080p30 with a bit rate cap. I know some Sony players only support Main Profile H.264 with AAC audio.