I had recently observed that the legacy barcode scanner in PA is disabled by default. You may want to check this in the app settings first.
If the feature was working fine earlier and stopped working recently, then you may want to try reverting the "Authoring version" of the app. This would only be a temporary solution and you may need to introduce the newer barcode scanner component.
Finally, if you want to see what's happening with your collection "colBarcodes", view it by going to ...