The Arcade expression fails to fully label features in ArcGIS Online Map Viewer and ArcGIS Experience Builder when the first fields in the attribute table are not filled out, whereas in ArcGIS Online Map Viewer Classic and ArcGIS Field Maps, the features are completely labeled.

Workaround

Change the Arcade expression so the features are named in the same order as listed in the data overview of the hosted feature layer. In this example, the field 'Hobby' is listed first, followed by 'FavoriteColor', 'FavoriteBook', and 'FavoriteAnimal' as depicted in the screenshot below:

So, the query becomes as follows:

$feature.Hobby + TextFormatting.NewLine +

$feature.FavoriteColor + TextFormatting.NewLine +

$feature.FavoriteBook + TextFormatting.NewLine +

$feature.FavoriteAnimal

or:

var hobby = $feature.Hobby

var farbe = $feature.FavoriteColor

var buch = $feature.FavoriteBook

var tier = $feature.FavoriteAnimal

if (isempty(hobby)){

  hobby = "."

}

else if (isempty(farbe)){

  farbe = "."

}

else if (isempty(buch)){

  buch = "."

}

else if (isempty(tier)){

  tier = "."

}

var label = hobby + TextFormatting.NewLine + farbe + TextFormatting.NewLine + buch + TextFormatting.NewLine + tier;

return label

Afterwards, the labels are depicted for all features in ArcGIS Online Map Viewer.

Steps to Reproduce