PAL - NTSC message

Following on from my previous post , where I outlined that if I shared my SS to bur as DVD , the file is created as a M4V file . When this is played in a DVD player , the slide show is stretched or created as a widescreen ,
but the vertical pix are truncated to square . I then just shared as a mov file , but I get this message “The TV standard is currently set to PAL,but all your content is in NTSC format.Do You wish to to write an NTSC disc or re-encode all content to PAL ?” see attached screenshot … Any answers?