Throttle Valve Fault code 0x21F9B1 help

I suffered by first ever stranded breakdown 2 weeks ago: complete loss of power . Engine did not stop but would not pull away . (The bike 2014 GSA WC low mileage and dealer serviced )
Recovery to dealer, who cleared the fault code and could not repeat the fault .Dealer suspected low battery voltage , because the battery was DEAD after 6 hrs roadside wait . Today, I have ridden 165 faultless miles. Putting the bile away tonight , I started it and rpm is too high at approx 2,000 rpm and very rough .Check engine symbol is displayed again . GS911 shows battery voltage 12.6V , Starts fine . GS911 says "fault Code 0x21F9B1" "Fault code meaning Throttle valve 2 (left) Initialisation "

This is the same error code that was presented to the dealer 2 weeks ago and revealed in their tests
After doing the GS911 diagnosis,I started the bike again and idles OK

Something's wrong. Any ideas guys ?

Santa2512 on the forum had a throttle issue, recovered to BMW who fitted a new throttle with further issues, then waited for a throttle wiring cable loom.

I believe his bike is now fixed with the cable wiring job but now awaiting a suspension fix.

Maybe speak to him by PM for advice ??

I’ve done lots of reading and no definitive answers . Most have throttle bodies replaced ( which contains the throttle position sensor ), but many of those report recurrence . Others have a software re install and others have wiring from throttle replaced .
Hey , it’s back at my local dealers now . ( An alternative dealer; ie the only one that had time to help me , simply removed the fault codes and pronounced no faults found after a test ride . )
Most reports (strangely ) involve throttle valve 2 ‘ , in fact I haven’t seen a report involving number 1 .
Something is wrong but , unknown is ; what ?

UPDATE; I’ve spoken to Santa-2512 and he had exactly the same symptoms as my bike ; Idle revving high and no power to pull away . His bike was fixed by replacing the throttle plus it’s wiring harness .
Meanwhile , my bike is “needing a new throttle position sensor” according to my Motorrad dealer . (The TPS is not available as a seperate part and so an entire new throttle body is needed )
All confirmed covered by my extended Motorrad warranty
Time will tell if that’s fixed my breakdowns.

Now starting week 6 of this 'throttle position sensor' saga and now just over 2 weeks with my deal local BMW dealer (Who initially were too busy to look at my GSA. fault. )
"Throttle body replaced and the fault has come back after a test ride"
So they're now investigating the throttle unit and its associated wiring harness (Which I've already informed them , is what Santa-2512 needed to fix his similar fault).
(fyi, my bike is on BMW Motorrad's extended warranty )

Update ; June 26th breakdown to dealer 1, July 8th second breakdown to dealer 2.
Currently still awaiting a replacement ECU “which could be a couple more weeks for supply “ and could be longer for ‘workshop availability ‘
Will a new ECU fix the problem; who knows ….

Hopefully final update;
Replacement new ECU (£1,200 parts) fitted by local dealer and bike running very well indeed and 300 trouble free miles covered .
(So replacement of the entire throttle body (£450 parts) did not fix the fault code )

Other new issues to note ;
Average mpg now increased to 61mpg and that’s at 70mph ( my 2014 previously max’d at 55mpg )
Heated grips now nicely very hot , which they were not before .

So nice to have the panzer back on the road.