Amazon require GS1 barcodes/GTINs that are registered in your brand/company’s name. This requires you getting the barcodes directly from GS1.
The GTINS you got from Barcodes Talk will most likely be resold GS1 codes that will not be in your name at GS1. So in theory, Amazon will reject them if they check. While you may hear the occasional horror story, it seems that Amazon are not actively checking for resold GS1 barcodes on existing products.
In your case,
If the 5 barcodes have not been used yet then I strongly recommend that you discard them and get new ones from GS1.org
If you have already used some or all of those barcodes then I suggest that you need to be aware that there might be an issue that needs to be fixed in the future. Apart from that, I wouldn’t poke the sleeping bear.