it's breaking bud. but the graft union still bothers me. 

the bud breaking.. 

 

graft union is only half attached. other half is not attached/heal at all. 

 

 Looks like the branch may have been pulling on it at some point in time
and forcing the grafted part to open some.

Ours is very hard to see it anymore if at all , not breaking bud yet but they are swelling a tinsy bit.

Hopefully, and probably that graft will heal over.

The mulberries I ordered this year all but the Black Beauty have broken bud.  Pakistan, and Persians leafed out fine, so after seeing yours I'm wondering what is up with the Black Beauties.

I hope these nigras live up to the hype, because other than BB they are growing like gang busters.