Playback>Render Cache>Smart

I have just installed Beta version 8 and found an unusual glitch. In version Beta 7 I have been editing and colour correcting some DJI Drone footage. This is filmed in H.264 and wrapped as a MOV file. My PC finds it a bit difficult to handle so I usually set render cache to Smart and it does the job nicely.
With version Beta 8 I loaded the same film in and nothing happens when I select Render Cache>Smart. I have to now choose User to get rendering done to achieve a smooth output.
Asus P6TD Deluxe MB with 24GB RAM
Zotac GeForce GTX 1080 with 8GB GPU
With version Beta 8 I loaded the same film in and nothing happens when I select Render Cache>Smart. I have to now choose User to get rendering done to achieve a smooth output.
Asus P6TD Deluxe MB with 24GB RAM
Zotac GeForce GTX 1080 with 8GB GPU