I'm going to go a different direction here. Not meant to start an argument (and I'm just not up for one if it does). Take the following however you wish, use it or not, your call.

In my experience, when 2.4 is "glitching" it is nearly ALWAYS one of 3 problems:

1) Power
2) Power
3) Power

In the VERY rare instances it hasn't been one of the 3 above, then the problem has always turned out to be power.

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Check batteries..under known load. Check any regulators/wiring/etc...under known load. Check all connections under known load. Isolate every single piece of the power system that touches (directly or indirectly) the Rx, including the Rx itself. The known load should be at LEAST typical load in flight, preferably maximum expected load.

Check for connections/components that are intermittent while vibrating or suffering shock. Wiggle cables where they enter connectors. Tap/shock batteries, the Rx, all cables, all connectors. Run the system with the engine running but each component removed, and isolated from shock/vibration.

Replace batteries (even if they test "good" temporarily with other batteries, as a test.

Temporarily remove any components that aren't strictly necessary for testing. Unplug all servos but one, for example. Remove redundant Rx/batt/regulator/etc.

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In short...think of every single path/wire/connection voltage goes through ANYwhere in the system, and test/remove it.