Thrustmaster Quadrant TCA Throttle incompatible with World Update 3, causes loss of electrical power

Do you have any add-ons in your Community folder? If yes, please remove and retest before posting.
No - all are moved out of the community folder for now.

Are you using Developer Mode or made changes in it?
No

Brief description of the issue:
The Thrustmaster Quadrant TCA Throttle causes a big (and strange) electrical fault that ends in complete electrical failure of GA aircraft I have tried, leading to MFD power-down, loss off electrical flap control, etc… It also causes a weird effect where the ignition/magneto key “twitches” as if an invisible hand was turning it side to side with a frequency of about once per second. This behaviour has been isolated as due to the TCA Quadrant (which received a patch in World Update 3 to fix that the engine buttons would not start the engine).

Provide Screenshot(s)/video(s) of the issue encountered:
N/A

Detail steps to reproduce the issue encountered:
Start MSFS with e.g. xbox 360 controller and mouse. Choose e.g. SR22 at EGGP for a short flight north to Waddington. Take off, fly, all is normal. Repeat, with Thrustmaster TCA Sidestick also plugged in. All is normal. Repeat, but now remove xbox controller and plug in TCA Throttle Quadrant instead. Strange behaviour starts as described. The battery meter shows the alternator is not charging the battery and it shows near the bottom of the yellow zone, where before it was in green. Eventually the battery gives up, the MFD shuts down and flaps do not respond to the lever, and their light is out. No-flaps landing forced. Repeat, without the Throttle Quadrant, all is well.

This has only been happening since I first started flying with World Update 3 yesterday. Prior to this, I have flown well in excess of 200hours in MSFS.

PC specs for those who want to assist (if not entered in your profile)
Alienware Laptop M17 R3/16Gb/RTX2070 4K monitor and the above controllers.

Did you submit this to Zendesk? If so, what is your ticket #?
I tried, but it seems not to be taking bug reports at the moment, which is ominous!

The problem is that the own control settings seem to have been changed during the update.

It was the same for me. For example, before the update I had set button 5 to “switch gear” and after the update suddenly “Gear Down” and “Gear Up” were on button 5. There were also other changes.

I made the settings again (as before the update), now everything is fine again.

Just try!

I am experiencing the exact same issues with C152, C172, C182, G58, SW121, basically all the prop GA I’ve tried. Citation Longitude, F-15, 787 seem OK after short flights.

Unlike Simson166 I did not find any changes in button controls.

There is another post reporting a similar issue - if not the same, see Thrustmaster TCA Quadrant ENG 1+2 - Engine buttons turn off Master Power - #6 by Growler22300, which has a temporary solution for this problem.

I posted this somewhere else by mistake! Oh well.
Thanks! Following your excellent advice, I changed button 3 which was operating Set Engine Master 1, Set Starter 1, Set Engine 1 Fuel Valve AND Toggle Engine 1 Fuel Valve to just SET Engine Master 1. I did the equivalent on button 4 for Engine 2. It strikes me as bizarre to have programmed these keys like this, they look conflicting even to a lay person. Anyway, my battery now gets charged by the alternator into the green and the ghostly hand has stopped fiddling with the key! Thank you.

See my post below. Did you check buttons 3&4? The update re-programmed them to hold strange, multiple actions.

The post above from Runaway gave me the temporary solution. I deleted the following from my setup of the quadrant:
Set Starter 1 Button 3
Set Starter 2 Button 4
Set Starter 3 Button 3
Set Starter 4 Button 4
That seems to have solved the problem at least on first flight with the C182.

i can CONFIRM the issue. i have the same thrustmaster airbus side stick combined with the quadrant TCA throttle installed with MSFS2020. worked just fine until a day ago or so when MSFS2020 was updated.

when i disconnect the thrustmaster TCA quadrant, the error disappears.