Edge 1050 terribly inaccurate gradient readings on 7k day.

I have the same issue. I am riding 15% slope and one time it is 7%, then 10%, even -2%, this is very  annoying.

Tell how to resolve this problem.

Thanks and best regards

He is referring to the immediate grade shown on chart and if configured also in data fields below chart. 

I have a new 1050 and have the same issue. I ride with friends and we compared ascent percent, My 1050 is increasing off (way low) as the gradient goes up. 

I rode again today and see the values working okay. So, it is intermittent, just not sure whether it's by ride, by distance, time, etc

Also, I do not have this problem on my Edge 830.

I think they put out new firmware that fixed the issue, because not only is it much more accurate, it is much faster at showing the correct grade.  I just noticed it the past couple of rides.

Nothing is fixed.

On Sunday, it worked completely incorrectly. On a 15% slope, it showed values ranging from -2% to 20%, and in the line above, where the gradient is also displayed, it went up to 40%!

There is an issue with the barometric device, and I will send it back.

I understand why there aren't many complaints about this issue—most riders rely on watt meters, so the gradient doesn’t concern them

Just came back from my today's mountainbike ride, which I used to check out the grade issue on my Edge 1050 ( v 10.19 ).
I set the native Garmin Grade field together with my IQ Edge Radar Speed Overlay field on a data screen. I always took screenshots then, when the gradient of the track was (more or less) stable and both grade data values had settled.

As you can see, most of the time the native Garmin datafield shows the (nearly) same grade as my IQ datafield, which takes only elevation change and distance change into account (with some routines and smoothing). 

But I have to admit, sometimes the native Garmin Grade datafield went crazy:

But these crazy readings lasted only for a view seconds and then they went back to reasonable values.
Yes, this behaviour is new! This was not with earlier firmware versions!

As a result, who ever wants a more stable grade datafield can try my IQ datafield. There is no radar device necessary for my datafield. Simply set "Grade" in the settings. For mountainbike I recommend a sample rate of about 12 seconds. For race bikes you can go down to 5 or 6 seconds.

My 1050 with 11.18 firmware is screwy. It seemed to work well for 30-40 miles and then even the native grade would just report bad values. Ugh. Like 0 or -1 on a steady sustained 3-4% grade. I need to rethink my CIQ app to handle Garmin’s bad altitude readings or whatever causes this!

I don‘t think, it‘s the altitude readings.
Have you noticed weird readings on your own Grade Calc, when Garmin’s native grade acted weird?