I have a customer that has been using the nRF Connect Mobile app on his iPhone to test his device and its works perfectly and he can do all the functionality he wants including DFU. When he uses the nRF Connect Desktop he gets an APP_ERROR_BUSY(0x11) when trying to enable the notifications or write to a custom characteristic.
The Desktop BLE version is 3.0.1. I have attached a screenshot of the error and the log file from the transaction. Please let me know your thoughts on this issue

