Dave i took your advice and got a USB 3 pic card for my mac which I’m sure would help generally
Thought this would solve the issue but it has not. I have however tried making new project with other footage an there is no issue with playback at all.
Maybe it is project specific. It was actually a project i opened which had previously been created on a slightly earlier version so it converted it as i opened it.
Might it related to this?
Any surjections gratefully received..its getting rather annoying now as i still need to work on this project
grrrrr