Buy shipping in bulk not printing

Hi all.
I’ve had a zebra printer set up for some time for buy shipping, however I’ve only ever done single orders as and when needed (IE: high value orders needing tracking etc). It marks them as shipped, prints the label, closes the screen and ready to carry on with what I do next.
Today I have tried to do buy shipping in bulk, it marks them all as shipped but doesnt print a single label and I am having to go and then find each order to ‘re-print label’!
Any help, ideas?