Has anybody discussed or mentioned radar failure/sabotage?
I ask this because inoperable radar would miss a missile or crash, or course deviation.
Whatever the case may be, since all other possibilities seem exhausted, start with the radar and go from there.
My other suspicion is a state actor. How or why, I don’t know, but it seems very strange nobody knows or isn’t telling.
The only question left to ask is:
"What difference, at this point, does it make?!
Which type of radar are you referring to? Air traffic radar has limited range. Military radars can see further but the ranges are not much more than ATC radar.