Why are my iPhone Messages still going to my old Android phone?

Recently upgraded my phone from a Motorola G power (Android) to an Apple Iphone 13. Ported the same number from the Android to the Apple. Carrier is Boost Mobile. I can send messages to all my contacts from the Iphone but some of their replies go to the old Android phone. Obviously I want ALL message threads to go to the new phone. Suggestions?

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