I believe that this can be enabled somehow, but I've checked all settings and found nothing regarding to the subject. While my EV changing everytime on my smartphone, it's always the same on RC and shows 0. All other parameters like height, distance etc. are changing everytime. Is this a bug or?

Hi, we're sorry for the inconvenience. I would like to ask if you've managed to use the right wheel or ISO/Aperture dial when the camera setting is in Auto? You may provide the firmware of your aircraft and remote controller. You could also provide us a short video showing this particular problem for further help. Please keep us posted on the latest progress. Thank you for your support.

If you're using auto exposure and its working correctly EV should always be zero unless you tell it otherwise.
EV =0 means the image is correctly exposed.

gnirtS Posted at 7-12 00:35
If you're using auto exposure and its working correctly EV should always be zero unless you tell it otherwise.
EV =0 means the image is correctly exposed.

On my smartphone it shows different values like -1.3, +0.3 etc. Depends on light conditions. I'm using M camera mode but with auto exposure. I presume that while the value is changing on the smartphone, RC must show the same value as well. I'm correct?

Auto exposure works by making the EV bias 0.  So it should always show 0 if it works and you havent manually dialled in compensation.

In manual the EV shows how over or under exposed an image is so will change depending on light.  This as far as im aware will NOT show on the RC.  The RC shows any compensation dialled in but i dont think from memory it actually shows actual over/under exposures in manual mode.

gnirtS Posted at 7-12 08:05
Auto exposure works by making the EV bias 0.  So it should always show 0 if it works and you havent manually dialled in compensation.

In manual the EV shows how over or under exposed an image is so will change depending on light.  This as far as im aware will NOT show on the RC.  The RC shows any compensation dialled in but i dont think from memory it actually shows actual over/under exposures in manual mode.

If it constant;y shows 0 in auto or manual mode so what is the reason of its location there? It doesn't makes any sense. Could you please try on your side to check that?
I tried different modes and nothing. I'ts still 0 even if on my smartphone current value is -1.7

Of course it'll show 0 in auto mode.  Thats what auto does and is supposed to do.
If you manually adjust the EV compensation it'll show something else, again as intended.

Its most likely the RC is showing the EV compensation dialled in.  So is not applicable in manual and unless adjusted will always be zero on auto.

Its trivial to demonstrate, you dont even need to take off.  Adjust the EV bias in auto and see if the RC reflects it.  Then switch to manual and see what the RC shows.