Zebra iMZ320 - line printing - stops printing midway



I am using a iMZ320 printer with the default out of the box settings i.e. no configuration.  I am using it with a lumia phone through bluetooth. 


It prints fine for most receipts but for receipts that are long...it stops midway through the printing.  It seems to stop at the same position everytime for individual receipts.  Is there a default character limit set for line printing (which is the default config on the printer I believe)?  Or is there something else I should be looking at?


Thanks for any help.