Question about chômage partiel (Paris)

Hi all,

I'm hoping someone among you can give me some advice. I currently work as a teacher at a grande école in Paris but I don't have a CDI contract. I lost quite a few teaching hours during the first confinement but I didn't receive chômage partiel. I understand that its not a legal requirement for employers to provide CP but I recently found out that some employees at the grande école did receive it. This semester, I have fewer hours per week than the same period last year, so I have 2 questions:

1. Am I entitled to receive the chômage partiel given that other employees received it, and can it be paid retroactively?
2. Can I ask for chômage partiel this semester given that I will be working less than the same period last year?

Thanks in advance for your help!