Barcode scan not working

My App/Pages Support link:

Describe the bug:
I am starting to play with the barcode scanner, but after successfully working once (using my PC camera) it did not work anymore. The app is not yet published. I have tried now to use it >10 times, but it did not work from the 2nd time.

Expected Behaviour:
It should allow reading the barcode and recording the text on dedicated rows.