we do update our data products from time to time. Usually we do so in case we find a better visualization for a product. We have also updated the data products as part of the migration to evalscript v3.
However, the behavior that you describe is not what I would expect from these changes. Could you please provide the whole evalscript or the first two blocks of your instance id (remove the rest to avoid potential abuse) and we can check in more details.
If you want to change your layer so that it returns only one band, use “Copy Script to Editor” button and then adjust the evalscript so that it returns only one band.