Climb Pro lags by between 60 and 160m?

This has to be with the issue with Altitude and Gradient. The Altitude is not correcly reflected in our units, it seems that the barometer included does not reflect the current altitude well. It's an open ticket right now that Garmin-Blake opened 4 months ago.

Hm, that might also explain why the recorded ride was about 40m less elevation than the Strava route suggested.

Strange...
Here‘s the opposite (by krazyeone)

https://forums.garmin.com/sports-fitness/cycling/f/edge-1030-plus/256393/1030-gradient-issue/1276225#1276225

I think, it all depends on the loaded elevation profile.

It could be. For me it is the same that for Lordmirg, it finish later, but as you said it should depend on the loaded elevation profile.

Regards!

On my last ride climp profile was 100-200 m ahead and climb ended 200 m before finish. Completely useless. 

It is really only as good as the underlying data that has to work with.

If you have time try the following test. Take you activity from the above ride and convert it to a course on the Edge. Then follow that new course and see if ClimbPro gives you a better experience using data from a real ride versus whatever planning site you were using.

As we all know the elevation data that all the sites use is based on 100x100m, 50 x 50 and at best 30 x 30m grids and the elevation for any other point between is based on a mathematical interpolation from the nearest measured points therefore can be accurate for flatish terrain but increasingly inaccurate as the terrain gets hillier. I have one frequent ride that goes through a deepish valley with a bridge over a small river that reckons the bridge is at 50m but looking at a topo map the 20m contour line goes right across the bridge, robbing me of 30m every planned visit!! Because the valley is fairly steep the measured points that could be 30-50m away could easily be 30m different in elevation.The Garmin barometric altimeter can give a better measurement if calibrated so using a previous recorded ride can give a better result.

Sure, but this unit does not have only to handle Grids, it have to manage it's own errors to provide a proper altitud value what you can verify if you save the track, then convert the fit file to route then follow the route. You will see that it not accurate either because of the device error.

So you will see two kinds of errors with Climb Pro. a) The track you download and the altitude data included (if it is not accurate donwloaded or converted to the route to follow) , and b) the device (in-) ability to measure the rigth altitude (that as of now for the mayority of the people) what is actually failing from the go live (and not fixed till now even with 5.0 firmware)

b) error:
climb pro does not look at measured barometric elevation.
It looks only at the loaded elevation graph at the current position delivered by GPS.