Why I’m missing many phone contacts on my contacts phone number?

Hi, otmane57,

Since there are many reasons that your contacts might be missing, we likely won't be able to pinpoint the specific cause directly. That said, we can check settings and perform other steps to help you recover them. Follow the steps below:

1. If you use iCloud, we would suggest starting by verifying if the contacts are still saved at iCloud.com. If so, you might just need to make sure the contacts option is enabled under Settings > [ your name ] > iCloud > Contacts. Then, you can use If you accidentally deleted your calendars, bookmarks, or contacts from iCloud - Apple Support to get help with issues syncing.
2. If you do not see your contacts at iCloud.com but know you were syncing them, try recovering them with If you accidentally deleted your calendars, bookmarks, or contacts from iCloud - Apple Support. Even if you don't think they were deleted (inadvertently or otherwise), they may still be able to be recovered using these steps.
3. If you do not use iCloud to sync your contacts, but use another account (like an email account), check directly with the email provider to see if the contacts appear on their site. If so, you might need to turn the feature on under Settings on your iPhone: Use other contact accounts on iPhone - Apple Support

If you still need help, don't hesitate to respond back.

Cheers!