Thank you for your answer.
But in the meantime I found the solution to my problem in an article from Microsoft.
In fact, from Android 10 there are changes in the security management according to the article : "With Android 10.0 and later, Android has removed device admin functionality. Instead, apps that require a screen lock query the device's (or the work profile's) screen lock complexity using the getPasswordComplexity API. Apps that require a stronger screen lock direct the user to the system screen lock settings, allowing the user to update the security settings to become compliant. At no time is the app aware of the user's password; the app is only aware of the password complexity level. "
So that's why the changes to be made are on the Exchange server and not on Intune:
I hope this helps others.