Mutual Interference
If the RFI turns out to be mutual interference, this wouldn't be the first time I've heard of such problems for radars with advanced waveforms and complicated automatic digital processing...
Does this set operate in X band, around about 9GHz like other airborne weather radar sets? I've not yet found an openly available spec sheet... A lot of ground based weather radars are at 5-ish GHz and there's beginning to be problems caused by 5GHz WiFi, especially if it's been hacked to improve WiFi range. If this set were also at 5GHz then it too would suffer problems with WiFi.