Note that this query is somewhat related to another post I just made on the forum, but I wanted to query more generally about the issue we're seeing without direct reference to the context in my other post which is specifically related to power margin.

Hello. My client is experiencing issues with RC link dropouts. The system description is below, followed by the description of the failure modes.

The platform is a customized Starling 2 / VOXL 2 (QRB5165, Ubuntu 18.04), SKU roughly MRB-D0016(?)-4-V?-C29-T7-M0-X? — I don't have the unit on hand at the time of writing, so the family and hw-version fields are unconfirmed. Some more system details are below.

Power: The drone runs on a 4S battery. The VOXL 2 receives its power via the VOXL mini ESC power module 5V output.

Cameras: The C29 M0173 front end. There's also a VL53L1X on the M0173 front end that's part of the C29 config, though not with a Lepton as shown in the front-end documentation, but as a single "rangefinder" as described in the rangefinder documentation.

Custom expansion: A custom hat board carries a connector that interfaces your MCBL-00022 harness and an AWUS036EACS USB Wi-Fi dongle. The hat also has connectors which interface four VL53L8CX ToF sensors modules (also your design, i don't have the PN for them) behind an I2C switch (the one you recommend). That is the extent of the expansion.

Failure Mode #1 (FM1) Loss of RC network bars on transmitter display. The RC transmitter stops showing link/network bars, suggesting the ELRS link has dropped.

• Occurs randomly
• Has been observed both at close range and at moderate line-of-sight distances
• Tends to occur around RC power cycling events
• Recovery requires multiple RC power cycles and is not guaranteed
• Not reproducible on demand

Failure Mode #2 (FM2) RC shows paired/connected but drone does not respond to input.

• Transmitter displays network bars indicating a connected ELRS link while the flight computer does not respond to RC input
• Suggests the RF link itself remains intact
• Recovers inconsistently after power cycling

Generally speaking, what is the recommended procedure to debug this issue? Thanks.