Auto ISO ok? Less sharp pics with Metabones 5

I'm just back from holiday and followed the Tony Northrup settings for my new A7III, on the EVF pics seemed fine, but in reality on screen they are not so sharp
My settings were as drive mode continuous focussing + AFC, auto ISO and I tested blue mode & advanced (red) mode on the MB5 adaptor.
First I had problems with the eye detection, it sometimes didn't work (Canon 24-70 2.8L MKI).

Today I changed some settings according to this video + I chose single shooting & focus mode single-shot AF and full raw.
https://www.youtube.co​m/watch?v=zPpelMC75lw&​t=13s

Inside I made some testshots and I notices the auto-iso chose ISO160 & ISO500 which seems very low.
With my Canon 6D I took shots at iso 1600-3200 inside, in both videos people rely on the auto-iso.

I know the Canon 24-70 2.8 isn't sharp wide open, but even at f5 or higher pics wheren't that sharp (auto-iso also).
Just tested with the pin-sharp Sigma 50 1.4 Art & eye AF and also focussing on the eyes, but again the eyes are not that sharp like the times of my Canon 6D.

Could this be because of the Metabones adaptor that degrades IQ or the built in auto-iso that isn't so accurate ?
I relied on both without testing before as my cam just arrived the day before we left on holiday, i'll adjust sharpness in PP....

Faststone image viewer directly recognised the ARW files, will check if PS & LR still need an extra update.

Why are you shooting auto iso ? Is there a benefit to it?

ISO has nothing to do with focus locking. It will only affect sharpness by either introducing too much noise or not being high enough to get an appropriately fast shutter speed for the shooting conditions.