Lumetri and transform preview not working

Hi all, 

Im having some issues with Premiere Pro. Midway through editing a project, my preview for any Lumetri adjustments no longer show on my video preview. I have to make an edit and then render it out to see what it looks like. If there are further adjustments, I have to keep doing that - make an adjustment, edit etc - it's all just guess work rather than being able to preview the live edits. The same happens with the transform effect. I've never had this issue before but it's started to happen all of a sudden making my workflow unnecessarily long and complex. I'm pretty new to the software so if there something I can do to fix this? 

I've deleted the app and reinstalled it but it doesn't work. I'm also now working off of SSD incase it was due to a storage issue. 

Thanks