Looker Studio Scheduler - PDF reports sent with errors

We have set up schedules for some of our reports to send a PDF version of our dashboard to our clients. Over the past few weeks, we have received complaints about PDF plots and scorecards that display errors, despite appearing fine when viewed on the dashboard or downloaded locally. I have attached an example of how the PDF is shown to our clients. 
 
Is there any bug in Looker Studio that could be responsible for this?