Flashing R9M "firmware update error, Device not responding"

[pomerus]

Hi

EDIT: Upgrading the radio from EdgeTX 2.7.0 to 2.8.4 solved the problem. The ELRS wiki on R9M says it needs "EdgeTX 2.4.0 or higher", so 2.7.0 should have been fine...

I am trying to upgrade an R9M 2019 from ELRS 2.3.0 to 3.2.1. All attempts to flash from SD result in the same "firmware update error, Device not responding". Tried on both TX16s, QX7. Tried 400K, 115K, 1.87M. Same result. ELRS LUA script is working and both radios communicating with the module no problem.

Didn't try re-flashing the bootloader, as I understand it is only needed to be flashed once, and not for every update.

Looked around in the forum, issues and google (and even Bing chat) - couldn't find similar issue(s)

All ideas/suggestions/help are welcome :)