Okular shows blank page on print preview

I've recently changed from CentOS7 to KDE Neon. I'm now using Okular instead of Evince to view pdf files. My pdf bank statements, which used to print out fine from Evince, are viewing fine in Okular but are just showing a blank page in print preview - and nothing prints. I've tried printing other pdf files and they're OK, it's only my bank statements which won't print out. Any suggestions? I can't see anything obvious about the files which might stop them printing.
I've copied the files over to an old netbook running Linuxlite and they still print ok from Evince.