STM32L041 Erasing through Bootloader UART doesn't work

[GVolo]

I use STM32L041 and trying to erase it through Bootloader UART. I am working on the 115200 baud rate and all bootloader commands work perfectly except Erase. I am using the Extended Erase command trying to erase all the chip:

0x44+0xBB-WaitACK; 0xFF+0xFF+0x00-WaitACK.The first time I get ACK (as should be), but the second time I am always getting NAC. What am I doing wrong?

[TDK]

Does the Get command say Extended Erase is supported? What is the full response from Get?