I've noticed that the select tool is pretty buggy in Experience Builder, when selecting a large number of features. I've embedded a video that shows how it doesn't select all features, when zoomed out and selecting a large number, but works fine when zoomed in.
Is anyone else seeing this?
I've certainly seen behavior like this. I believe there is a limit to the number of features that can be selected. Can you confirm how many points are being selected in the video above? You could add a text widget that shows the COUNT() of the selected features to make it easier.