Moving the conversation off the dating app?

I met a guy on a dating app. After (very) briefly texting, he asked to move the conversation to WhatsApp, claiming he wasn't receiving notifications from the app. I agreed and gave him my number. I then found out that he had actually blocked me on the dating app. I thought that was weird, so I stopped communicating with him. I'm not sure if it was right to give away my number this soon. Was this a red flag? Is this a normal request from guys?