Prefab became randomly inaccessible

As the title say I have a script that I use to store prefab. Sometimes when I call it, it say the prefab do not exist even if they are well assigned in the Unity editor.

The temporary solution I found was to delete the script component in the editor then re add him and re put each prefab in there assigned place.

I think this may be a pretty commun issue but since it append for no reason I may need advice.

(My unity version is: 2022.3.28f1)