Galaxy S7 clips.  Are they variable framerate?  If so does the problem still exist if clips converted to fixed framerate?

It seems to be using all the CPU and almost none of the GPU.
I'm lost!

What did you thought the GPU would do?
Normally the GPU's have to give picture on your monitor and sometimes it helps for smooth playing some added video-effects ( in this case the hardware acceleration), but if you are not using effects that use that kind of acceleration (listed in the FX tab)
it does nothing but only giving you picture on your screen and all the rest uses your CPU in combination with the amount of RAM.
We are not talking about rendering here.

I thought that the playback would use the GPU, evidently not and I'm on a learning curve!
Is it normal though for my CPU to go up to 100% just playing back a sped-up clip?
I wouldn't care what was happening in Task Manager if the video was playing back normally, but that's clearly not the case.

Galaxy S7 clips.  Are they variable framerate?  If so does the problem still exist if clips converted to fixed framerate?

Just spent an hour searching around for info on this and I'm none the wiser now!
I can't find the info to tell me that the S7 shoots variable framerate but it would seem so as the iPhone does.
I found a script for FFMPEG that was supposed to convert variable to constant framerate, but, though the script ran, I just got a 0KB file as my output.
Read about Handbrake to convert, but too many are complaining that that also doesn't keep the audio in sync with the video.
I read another post which pointed towards using an app to keep the framerate constant on the S7 whilst shooting, but that obviously doesn't help me here.
Any tips on how to achieve this?
Am I so naive thinking that I can shoot a video on my S7 and to expect the latest version of one of the best NLEs on the market to be able to edit it?

Can you give a screenshot of your VPro 16 Options/Preferences/Video?

I just created a proxy for the clip which was sped up and it worked fine, which (I think?) it would suggest it must be something in the S7 file that VP doesn't like.
So it looks like I have to create proxies for all my clips from now on.
Is this a normal workflow procedure for anyone else and does anyone else edit S7 footage?

I can see that proxies are the way to go in this case, but I don't have any 4K media,

I dont get this.
You use not 4K media, but why do you edit in 4K projects?
With your hardware I think that only when you use 4K media to have to use proxies in a 4K project.

Can you give a screenshot of your VPro 16 Options/Preferences/Video?

Sorry I don't understand your question about "editing in 4K projects".
What am I doing incorrectly?

Sorry I don't understand your question about "editing in 4K projects".
What am I doing incorrectly?

I'm not saying that you do something incorrect, I only don't understand that you use a 4K project when you say you "don't have any 4K media" in this comment.
Using HD or lower sized videofiles in a 4K project forces the program to resize those files first before use them in a 4K project.
Seems not logic to me and is also an extra heavy task for the CPU, specially because you dont use proxies I can see at your screenshot.

Sorry I don't understand your question about "editing in 4K projects".
What am I doing incorrectly?

I'm not saying that you do something incorrect, I only don't understand that you use a 4K project when you say you "don't have any 4K media" in this comment.
Using HD or lower sized videofiles in a 4K project forces the program to resize those files first before use them in a 4K project.
Seems not logic to me and is also an extra heavy task for the CPU, specially because you dont use proxies I can see at your screenshot.

My bad, I'm really sorry.
I appreciate you taking time out to help and it's frustrating when I'm not giving you the complete and correct information.
I'm used to editing GoPro video and video from my Canon 5D and, to be perfectly honest, I forgot that I had my S7 set at UHD. I never even realised that this was "4K", which is pretty dumb in retrospect.
So I'm correct in thinking that I should always use proxies with S7 footage set at UHD (4K)?
I just ran Task Manager again whilst playing back a few files that were sped up and my CPU didn't go above 40% and it doesn't glitch at all.