Sonoff RF Bridge Tasmota wrong install

I have a Sonoff RF bridge that I accidentally upgraded with a wrong version of Tasmota for zigbee bridge and now I am unable to configure it as an RF bridge. I am also not able to install any other firmware (minimal, lite, tasmota, nothing…) as it always says not enough space. When I try through the console, Failed Update error: ERROR[8]: Flash config wrong real: 1048576 IDE: 2097152".
Can anyone please help?
Many thanks in advance