Hello,

I’m using an E73 (nRF52840) module. After flashing the nrfmicro_nrf52840_bootloader-0.8.0-dirty_nosd.hex bootloader, the nRFMicro drive appears correctly on my computer, and the onboard LED shows a breathing pattern — everything looks normal at this point.

However, when I drag and drop my zmk.uf2 file onto the nRFMicro drive, the LED changes from the breathing pattern to a short blinking sequence for a few seconds, and then the nRFMicro disk reappears again, as if nothing was flashed.

When I use other bootloaders, such as

• nrfmicro_nrf52840_bootloader-0.5.0-dirty_s140_6.1.1.hex, or
• pca10056_bootloader-0.2.11_s140_6.1.1.hex,

they both work normally without this issue.

Could you please help me understand why the 0.8.0 nosd bootloader cannot flash the ZMK UF2 properly?

Thank you very much for your time and for maintaining this project!

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