RAK811 wont exit boot mode


I have bought RAK811 ver 1.2 (RAK811 Version: and it worked just fine until I run the command “at+set_config=device:boot”.
I got the following response:
Work in Boot mode now…

Since then for every at command I write I get the following error:
AT cmd error.

I try to return to normal mode with “at+run” and all I get is:
AT cmd error.

I press the reset button and get:

Does entering boot mode erase the current firmware ?
Is the only way to leave this state is by flashing new firmware ?

PS: I use Linux, is there a way to flush a firmware in Linux ?

PS2: I had to put space between the opening brackets and the words “BOOT MODE” or it wouldn’t print.