The update seems to screw up Eye AF. After 1.4.0, my R5 would often not find an eye when I knew from past experience that it should. Someone else said it turned off eye detect and I'm almost sure mine was on but as soon as the batteries get charged, I'll double-check. Several other members of Michael the Maven's R5 group reported the same bug.
One thing it did on mine was turn on touch display to take a picture as I never use that. I'm going to restore my configuration file from the last firmware update and see if that fixes eye AF as I can't believe this wasn't caught in testing?
I figured out the problem and fix the 1.4.0 update bug. After installing 1.4.0 firmware update, it changes the AF Method which turns off eye detection and turns on touch display to take a picture!
Go to AF and 1st tab, change AF Method to the first selection. Then go to Eye Detection and enable it.
I also turned off the touch display to take a picture.
I'm wondering if the software developers take an image of the camera's setup and incorporate that in the firmware update. This means your camera ends up being set like the person who's testing the firmware. What they should do is reset the camera or configure the update such that it doesn't change any user settings? IMHO