I HAVE A FIX!!!!!!!        So I have a Mavic Air.. My right joy stick was aslo controlling some parameters on the left.  I unscrewed the sticks and prayed electric contact cleaner in and exercised it. Screwed the sticks back on, tested and BAM...  FIXED THAT CHIT!!!!.  I did not have to take it apart.

I am so disappointed.  I bought this new dji mini SE on amazon only a week ago. Today i am powering it on for the first time and have the same annoying beeping sound on start up. Did everything dji tells me to do to fix this issue... recalibrated the joysticks countless times.
The right joystick is not working properly. In the calibration app it shows thst it acts crazy whenever i move the left joysitck.
I am especially disappointed because i travelled back home to a far away island in the Caribbean. Just the shipment costs and customs handling fees would be almost the same price of this new device    any suggestions anybody?

Hello All!
I CONFIRM THE FIX!!!

I've got exactly the same problem with my DJI Mavic Air RC (3 y/o, so, no warranty for me) :

- beep-ing when power ON my RC;
- initial calibration screen shows - my left stick is 18% "forward" (that's why "beep-beep-beep" on start)
- when calibrating - moving e.g. right stick down, also shows my left stick down (which is wrong, of course)
- when flying, especially backwards - drone moves back-and-down.

Thanks "fans9dfdfc94" for posing the YouTube video - "DJI Mavic Air Controller Joystick Problem FIXED - 4K" it really helps!
So, my process looked like this:

1. Main "actor" - WD-40 Specialist - Contact cleaner! (7.50 EUR) . Plus, we have RC itself, screwdriver, some plastic disassembling tools from eBay.


2. Actually, the most difficult part for me was opening the plastic body. I tried to be careful, not to crack the body, but... with "baby steps" forward - I'm done:


3. Back is opened:


4. RC is fully disassembled. Back side of joysticks is marked with red color:


5. Took out the 2 modules and with high pressure stream from the WD-40 Contact cleaner
cleaned the marked places (with green arrows)
Please, note, that due to high pressure of the "Contact Cleaner" contents I even didn't take off the yellow plastic "protectors" of the potentiometers.
It worked even without future disassembling!


6. Leave them to dry for ~30 min (just to be sure they are completely dry), I've assembled the whole RC back.


And... Voilà!
Have tested it already. After the 1 more calibration - no more beep-s, calibration indicator shows 0% movement of "other" stick.
Yyyyessss!
Took my birdy up to the air aaaaand... - perfect! Fly backward smoothly. Absolutely no loss of altitude.
Even I think, that it become more stable when "standing" still (without stick movement from pilot).

So once more: BIG thanks for instructional video. It works!

Fly safe.
Peace!