BLE ReceiveStrings issues

I’m using BLE extension wich can be downloaded here : MIT App Inventor Extensions

I’m trying to receive some datas from sensors, but I have some issues with receiveStrings buffer about changing the device name.

Device name is Hello.
I read the name in my app.
I write AB as new name.
I read new name.
It looks like being “AB lo” but apps like EFR Connect prove that AB has correctly been saved as new name.

When BLE Connected

When SendNewDeivceName Button click

Is there any solution ?