Colorgrading: No wave forms visible

Hi! I´m a total beginner with DVR. So, every thing which is not like in the tutorials bother me
Ok, I would like to start with the color grading. And in every tutorial I see these wave-forms on the bottom right. But with my videos: nothing....? As you can see in the attachment. I have not the faintest idea why not. So I would be very happy if somebody could enlighten me.
Thanks

Try this setting.

Thank you for your advice!
But, as you see in the picture, that does not seem to be the problem.
But then, what is the problem?

What's your hardware ? And the drivers version ?
Is that beta 8 ?

Also, try disabling gpu scopes in the preference.

Intel Core i7-4790
8 GB DDR3
Mainboard: MSI Z97-G43
Grafic-Card: nVidia GeForce GTX 750
SSD 240 GB
Windows 10 home
Version 1909

driver for the grafik-card: 27.21.14.6079

In preference gpu-processing - no hook
in gpu selection - no hook
Selected: CUDA

For the DVR version: I could not find the normal HELP file with system Information, only: public beta - DaVinciResolve 17.
BUT: When I looked for the actual driver version, I saw that there is a new driver version and after installing: Yeah, the waves are there!
So, without your help I wouldnt have had these idea to have a look at the version.
Thank you for help.
(and I know, my system is a bit weak for DVR - but I´m waiting for some RAM sticks and I´m looking for a better grafic-card (but they are exeptionaly expensive just now).