Newbie needs help with save games

[LC667]

Hi guys, I have the current version of the recalbox running on my rasperry. What I found out is that I can save some games and some not. Is there any logic behind this? For example I can save some games on the sega master system (Alex Kidd) and some not (e.g. Shinobi). Any ideas how to solve this or is this depending on the games itself?

Thank you for your answers!