I moved issues from one porject to other project , Issue keys are strange

Rasajna Meka_dbri80

I moved 2000 issues from one porject(A) to other project(B) , Issue keys generated are absolutely fine but if I create new jira in project B after migration the issue keys are started generating with a number of 70000 . Can someone help me out understand the problem

Nic Brough -Adaptavist-

This suggests you already had 68,000 issues in project B.  Is that right?  If not, then what do the pre-existing issues in the project look like?