Contacts were not transferred over to the new device

I recently leased new iphone xs and I have noticed that contacts that I previously have saved on my previous iphone were not transferred over to the new device. People would text me and the number is not identified by the phone so I have to look at the conversation history to figure out who is it that is texting me. Sometimes I get a call from someone I know for a fact is saved on my contacts and it doesn't show on my screen other than just a simple number. Also if I want look for someone n my phone book to call them it doesn't even show the name as it is non-existent on my device. Please help me because I use my phone for work and it is really concerning. Thanks.

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