R2 remote problem

Hi guys,

I have a problem with my GTX (bought two weeks ago) since this afternoon...
1- I ride in ECO mode : it is ok
2- I switch to Fast mode during my ride : it is ok
3- but when I try to switch Fast to ECO during my ride, my remote R2 not responds anymore and I have to brake with my feet... : It is ko. And after I have to try many times to reach apair between my board and my remote again...
This arrives always since this afternoon

I have already follow the video to reset my setting trigger

Could you help me plz?

Thanks in advance,
Romain