It's possible that the second HDMI port on your Raspberry Pi 5 isn't recognized by recalbox due to a lack of implementation or activation parameters. Since you'd prefer to avoid using an HDMI hub and instead select which HDMI port to use through the menu, you might want to check for any updates or patches that enable this feature. Alternatively, you could explore configuration options within recalbox or the Raspberry Pi settings to see if there's a way to activate the second HDMI port manually.

@scavy
ok, merci pour ton retour. Je viens de commander le kit.

Thank you very much for your support. If you have found any other way, please tell me to test it. I have no problems at all in testing the various ways and in helping with the future functioning of the system. I look forward to more suggestions.

@barbudreadmon Je pense que c'est général. Les prix de la RAM ont augmenté et la "crise des composant" qui court depuis l'année dernière n'est sans doute pas étrangère a l'augmentation, qui a touché également les Pi3, et d'autres cartes.
Je suis assez épaté que le Pi4 soit aussi peu cher, mais je pense que la fondation Raspberry à fait des efforts énormes pour pousser son nouveau produit.