Let's stop talking about possible contributing factors and focus on cause.
I donīt know how to do this without delving into contributing factors since there can't be a single cause.
Avoiding weather will not cure this problem since someone somewhere in the sky always fails at the avoiding part
In the end, corrective action redesigning speed probes will not make this go away (everything we design ultinately has a failure rate).
Redesigning the avionics means a few years and retraining all the pilots before it can be used.
Iīm afraid that we`re going to have to make do with what we have for a bit longer and learn how to live with it.