Cannot connect to nRF52840DK board using nRF Connect Bluetooth Low Energy app on Linux (Ubuntu 18.04 LTS). When I choose "Select Device" and choose my board, I get:
"Validating connectivity Firmware..." followed by "Error while setting up device xxxxx. Permission denied, cannot open /dev/ttyACM0"
Port ttyACM0 does exist, and most strangely, if I run the Programmer app under nRF Connect, it works fine. It can connect to the board and perform all operations. The same board run under nRF Connect / Bluetooth Low Energy on a Windows 10 PC works fine.
I did recently update both nRF Connect and BLE on the Linux laptop to v3.2.0 and 2.3.1 respectively. The Windows PC is running nRF Connect v3.0.0 and BLE v2.3.0. I am afraid to upgrade either until I understand what is happening with the Linux installation, as it used to work.