This topic has been covered a few years ago but I'm hoping the situation has changed since then. It doesn't look like with the current ArduinoBLE library you can configure a Uno R4 to be a client as well as a server at the same time? One person a few years ago seemed to suggest they got it working (setting up Event handlers) but no one was able to replicate.
Has anyone got it working?
I don't know why this worked but I removed the event handler for 'discovery' and now I can run in dual mode BLE.
This was the line I removed. It only output a debug message to the serial port anyway.
BLE.setEventHandler(BLEDiscovered, blePeripheralDiscoveredHandler);