Some of my contacts are not synced with icloud

Welcome to the Apple Community.

1. First check that all your settings are correct, that contact syncing is checked on all devices (system preferences > iCloud on a mac and settings > iCloud on a iPhone, iPad or iPod).
2. Make sure the contacts you are adding are added to your 'iCloud' group and not an 'On My Mac', 'On My Phone' or other non iCloud group (you can do this by checking in groups), non iCloud contacts will not sync.
3. If you are sure that everything is set up correctly and your contacts are in the iCloud group, you might try unchecking contact syncing in the iCloud settings, restarting your device and then re-enabling contact syncing.

If it's on a phone, you might try the following, I haven't done this myself.

Go to settings > iCloud and disable contacts, when prompted opt to keep them on the phone.

Then re-enable contacts and opt to merge when prompted.

You could share the contacts to yourself by message or mail.

You'd need to ensure your iCloud account is the default account and once you've made sure they are then in both accounts, you could delete them from the hotmail account.