New BeA gun misfiring This could be an air pressure issue. You should not overpower the stapler, but use the maximum allowable air pressure for the devise. Look at your pressure gauge when the trigger is pulled to see if you have the correct setting. Hose size and length ca affect the performance output of the tool.
If you still encounter issues, there may be a physical problem with the tool and it may need to be serviced. You said it was new, but new tools may not always be assembled correctly and can have damages components from the assembly process..