Hey @Selwha
can you run your sending subdomain and root domain through whatsmydns.net or dnschecker.org? Klaviyo points to both in their activation troubleshooting steps. If the NS or CNAME records don't show up publicly, or your DNS is on Cloudflare with proxying turned on, that could be what's holding it even with green checks in Klaviyo (troubleshooting guide). Also, is this root domain connected to any other Klaviyo account that uses a different sending subdomain? That has caused this same block in other threads here, and only Klaviyo can see it from their end
I will tag @GabbyEsposito @Temi O. here so that they can escalate this to the correct people on Klaviyo's side.
also i would suggest, once it unlocks, pause your flows and hold any scheduled campaigns before you click Activate, since this is your first marketing branded domain. Then send a test and resume.
I hope this helps and thank you for sharing your question here in the community.
Cheers
Arpit.