For some reason the AEL button on the rear of my X-T4 is doing nothing; i.e. I press it and I don't see the AE lock symbol to the right of the metering icon - either temporarily (when the button is held down) or permanently (when the AF/AE buttons are set to work as an on/off switch rather than push to hold).
This is with an Fujinon XF lens. I've tested it in both manual and auto bracketed ISO, and in all focusing modes, and all metering modes.
I've also checked the button is assigned correctly (to AE-lock only) and verified it is physically working by assigning it to something else.
Additionally, setting AF/AE lock mode to "switch" (Button/Dial setting menu) doesn't seem to have any effect on the 'AF ON' button behaviour - i.e. AFL is still only shown on screen when the button is depressed, not toggled.
Update: A fix for that problem is to change the button assignment for AF-ON from AF-ON to AF LOCK ONLY, then pressing it toggles the blue AFL indicator while back-button focusing still works in manual mode.
Face-detection is OFF (apparently this stops various other things from working).
I've done a Set Up Reset too.
v1.24 v1.30 (lens v1.05) - both latest versions