Re: "US, Canada finally ground 737 Max jets..."
"A grounding of all planes of that model would disrupt airline schedules, and so I think they wanted to avoid that happening. Now that there's evidence to ground them, safety first."
From what I've been reading over the last few days, there has been evidence aplenty, particularly for South West Airlines pilots that MCAS is a pig and Boeing have been working on a patch for some while because they already know there are issue with MCAS. You don't spend time and effort fixing something if it's not broke. And if it's not broke, you leave the patches or fixes aimed at improvements for the next release cycle.
As this is basically a new aircraft with news system, does it not seem odd that Boeing are creating a patch that stops the MCAS fro going to full negative or positive trim unless that situation has been reported to them as a problem?