Blocking someone on iPhone, still showing in messages on mac

Thanks for reaching out for help in Apple Support Communities. It sounds like you've blocked a certain contact but they're still able to reach you by text from your other devices. It's possible to be reached by iMessage from an email address that the recipient has set up to use with iMessage. In order to keep all contact info blocked, follow the steps in the link below.

Block phone numbers and contacts or filter messages on your iPhone, iPad or iPod Touch

Specifically, use these steps:

Phone

Go to Settings > Phone > Call Blocking & Identification.

To add a contact, scroll to the bottom of the Blocked list, tap Add New, then select the contact that you want to block.

Let us know if this helps.
Take care!