It is not recommendet to use systems that rely heavily on GPS/Compass during periods of a high "K-Value" see...

SPACE WEATHER PREDICTION CENTER

There is a history also, maybe you guys with drop outs or fly aways can check them against high K values.

A drop out because of the K Index? How should this work? Mode switching to Atti could be, but a drop out?

Well true I can not make something up that a dropout is caused by a high k-value. But if I am right there are also lots of compass error and GPS signal problems reported.
Actually it was meant as a funny side note to check against problems - but every copter pilot who uses GPS/compass should be aware of interference from solar flares and the last 30 days where quite heavy on those.

Maybe the DJI Go 4 app should check against the prediction and display at least a warning that flying can be problematic

I always check the K-Index prior my flight using the "Magnetology" app on iOS