Can't Load Some Websites (HTTP and HTTPS) After Public IP Migration

Has anybody had issues accessing websites after a public ip migration?

We have two HQ offices with separate public ip spaced. We only changed our public block on one of those two locations.
The location we didn't change we have no issues. We noticed that a few trivial sites (trivial so far) don't load and just hang before timing out since change our public ip block. Looking through logs I see no blocks. Even when I capture on the firewall at the edge, I see SYNS leave from my attempts but no SYN/ACKS come back from these sites. We've checked with some of these sites so far to see if they've blacklisted our new public range and the answer has been no.

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In the past, i've had issues when after installing new edge routers or getting new ISPS, you have to clear your arp tables because your gear may be hanging on to stale l2/l3 info. I'm wondering if there's a layer 4-7 version for what I'm experience? Any ideas? These sites all load fine externally and or from the site we didn't change the public space on.