Called a blocked number

[AC Question]

I'm on iPhone and called someone who I suspected had blocked my number (they are on Samsung). I turned my caller ID off but they then messaged someone to ask why I was calling because it was clear they blocked my number? How do they know it was me if I hid my number?

 

[belodion]

Is this you? https://forums.androidcentral.com/showthread.php?t=777503