Hotmail contacts not syncing

Hi everyone,

My iPhone suddenly stopped syncing Hotmail contacts correctly. Some of my Hotmail contacts are not synced with my phone. I got 106 Hotmail contacts (pure Hotmail contacts, not Facebook, Skype nor Messenger contacts) and my iPhone shows 86. There were showing correctly yesterday. I've turned off contacts and turned it back on, and still syncs only 86 of my 106 contacts.

I noticed that all my missing contacts were Messenger contacts before, and since I turned them to Hotmail contacts (unlinked them from Messenger), they don't appear in my iPhone's contact list.

Can this be bug in Apple's syncing with the Hotmail service?

Thanks in advance!