Successfully printed statement as pdf.
Elected to save pdf to… phone hung, white screen.
Selected next statement - no response
Selected different statement - no response
Selected another statement - rotating timer then Monzo error message like ‘timeout bad gateway’
What phone you’re using - Just tried this and there was no problem for me downloaded on to my phone.
IPhone 7 iOS 11.2.6
Tried several save to options successfully.
Save ‘to files’ on iCloud caused hang again
Rebooted tried all save to options and this time all successful.
Finger may point more at iCloud app.
File as solved