I am using nRFConnect with nRF52840 Dongle. Since the last update to SoftDeviceAPI v5, nRFConnect cannot connect anymore to this specific devices (cheap JDY-10 BT/Serial adapters). Here there are more details and logs:
github.com/.../161
Sometimes the device cannot be even discovered, then I remove the USB dongle re-insert it and the scan finally find it, but still cannot connected.
As I wrote on GitHub, the device can be always found and connected if I use the Android App BLE Scanner.
I am not sure how can I help in diagnosing the issue.