Not really weird considering Orbs have zero hit/block stun and b2 is 15f start up. If you use the wrong normal or string into Orbs and then b2 you're bound to get interrupted one way or another, especially if you're 1 frame late with your links.
b2 xx trait, b2 and 22b1 xx trait, b2 are not really good blockstrings. If you're starting with b2 xx trait you should go into 11 or 22b1. And if you start with 22b1 xx trait you should go into 11 or possibly another 22b1 but I'm not sure. 11/22 xx trait, b23/22 is good on block also.