Panasonic DMR-E50---DMR E-65

Hi , new here :bow: A question that has bugged me !

Can anyone tell me why the DMR-65 can read unfinished discs from the E-50 but not the other way round ? If you put a disc in from the 65 with time left into the 50, it displays no time (space left) ?

Oh, and Could anyone tell me if Taiyo Yuden media will work with these recorders, the only success i get is with GO5 Dye discs.