FC partial shutdown during flight - 2026.6.0-rc1 - AXISFLYING F405-ECO

Describe the bug

The same quad has been built before but with different electronics, but same overall setup. Tune and all were copied.

The quad has the following issue:

Randomly during flight, it appears to have a "motor desync". Logs show classic saturation of motor output.

However, eRPM frames are frozen and the voltage in the logs drop to 0V, even tho voltage is measured with onboard ADC. OSD and connection stay intact, please see the onboard video. OSD voltage from betaflight and DJI OSD also drops to very low value in OSD.

Logs

One instance, logs stopped right before "shutdown", OSD and all other connections continued, quad crashed. Two instances, logs continued until disarm. Other instances, no logs were recovered but OSD video is available.

Here are most of the logs (cannot share everything): https://drive.google.com/drive/folders/15NWtaUTNhy8ztUMvu90XtPK3Ut1DTHDk?usp=sharing

To Reproduce

This was my testing so far:

• Maiden flight crash: I flew without camera payload and had really noise motor output, shutdown happend some seconds after launch.
• Second Crash: Also with no camera, quad survived a bit longer than on the maiden
• Blackmagic Crash: Final tuned quad (but no fresh props), with full payload and circa 4 packs in between that I felt confident were nothing happend. Tune should look kind of right in this one.
• Final tune: Here I used fresh props, no crash happened here. Setup then stayed like that. Just for completeness
• After that circa 8 packs were flown at really high speed and pushed the quad to the max (was on a shooting), after that one more crash happend and chill flight (no logs), now I'm writing this Bug Report.

In general its hard to reproduce, in the begining I thought hard moves (curret spikes, tune on the edge, etc) trigger it by ESC desyncs. But looking at the logs I suspect the FC to partially shutting down, which is shown by eRPM freezing and especially the onboard voltage measured on the FC to drop to 0V.

Expected behavior

Quad does not drop out of the sky suddenly

Support ID

21529055-eeed-441e-a911-80815d0bda0a

Flight controller

AXISFLYING F405-ECO

Other components

• Axisflying F405-ECO 8s FC
• T-Hobby V70A 8s AM32, newest AM32 FW
• Flywoo GM10 Mini V3
• HaloRC Cygnus 7 inch frame
• DJI o4 Pro
• Radiomaster XR4 in X150 with Nomad TX
• XNOVA 2808 1500kV
• Panasonic 1000µF Cap 50V
• 1600g AUW, carrying a Blackmagic Micro Studio G2
• 2600mAh 6s Battery

How are the different components wired up (including port information)

All with pre-crimped wires from component to FC. UART1: o4 air unit pro UART2: AM32 ESC with telemetry, part of the harness from ESC to FC (Bat, GND, Telem, Current, M1-4) UART4: GPS UART5: XR4

Add any other context about the problem that you think might be relevant here

Second issue: OSD elements related to GPS randomly disappear during flight, as far as I know that means that no GPS is detected by Betaflight. I just found out that could be related to my baud rate setting since the GPS module has default of 115k, but might be related to something shutting down on the FC