Need help GR64 R5A AT*E2STKTO respond error


I buy GR64 R5A. Sim toolkit repeat ESTKITEM too fast. I can’t select item. I found ATE2STKTO to set time out.
It respond ERROR. I’m try to download R5A for upgrade. Zip file respond “damaged”.

My old GR64 R4A. It respond ok. not need to adjust.
Can i reverse from R5A to R4A?


yes you can !

Just ask firmware R4A to your distributor.


Thank for help.

Have any way to set timeout without using AT*E2STKTO?
I found R5A is faster than R4A.