[Koha] Spine label printing

[TS Library]

I have recently purchased a Dymo LabelWriter 450 Turbo to print spine
labels individually rather than in batches.

I have set SpineLabelAutoPrint to 'do' and set SpineLabelFormat to
<span style="font-size:13px; line-height: 90%"><itemcallnumber></span>
This was following advice I received from a list member.

When I click on the link to print spine label next to an item the print
dialogue box comes up and displays the Dymo label writer at the top but
nothing is displayed in the print preview – just the little blue dots going
round in a circle – and if I click on print nothing happens. If I change
the printer name to Epson which is my main printer the label is displayed
in the print preview and I can print it.
Can anyone suggest what I am doing wrong?

Jo Atkinson
Theosophical Society in New Zealand