Same situation with my new X-T4.
The camera freezes occasionally - sometimes when switching something on it (e.g. from Movie to Photo Mode or back), sometimes after taking a photo and sometimes it won't wake up again after going into Sleep Mode...
The one and only solution to get my X-T4 working again is to take out the battery and put it in again.
I tried several SD cards - from old ones to brand new UHS-II U3 with V90 standards...nothing changed.
And when I switch between the XF 16-80mm 4.0 lens and the 23mm 2.0 - nothing changes at all.
And yes - I got the latest firmware installed on the X-T4 and on the lenses.
Sadly it is not possible to reproduce the error - it occurs randomly.
Never had such issues with any other cam I owned...not matter if Nikon, Canon, Panasonic or Olympus.
I am really disappointed 😞
