You may have had a couple of unrelated problems. Not once in your description did you mention the condition of your transmitter battery. What the original problem may have been is a transmitter battery that was marginal or approaching discharge. I would seriously check the batteries in your transmitter before going any further with your diagnosis of the problem.

Depending on what radio you are using, and at what frequency.. if using one of those cheap radios that come with some of the inexpensive RTF electrics, it probably is operating on the CB band and may be getting intefered with.. you never know. But if operating in the RC 72 MHz band, then this is pretty unlikely unless someone turned on their TX while you were flying. Glitches happen, but to have something like you describe more describes a dead or dying transmitter battery.

I would rule out forgetting to pull out your TX antenna if you say you got two good flights out of your Stryker, but it is possible.

CGr.