Hello Paul,
Thanks for reaching out to us!
This is definitely a strange issue to be having. Hopefully I can help you to get this cleared up quickly.
First off, have you tried following the Testing for Conflicts procedures to see if this is potentially a plugin or theme conflict? This will help us to narrow down what may be causing the issue.
I’m sorry I wasn’t able to give you a direct response however I hope this was able to point you in the right direction.
Thanks!