The machine is not registering a tag has been inserted into the machine/backside of the tag does not work.

If the machine is not “reading” (so the carriage does not go inside after the tag insertion) the back side of a tag:
1) the tag packaging is damaged, so please verify there is no damage to the casing of the tag.
2) Make sure there is no plastic debris that is blocking the sensor at the end of the carriage where the tag would normally sit inside the machine.
Here is an example:

If you see a clear little piece of debris, you can use compressed air or a paperclip to remove the debris from the carriage.

To raise the portcullis, it is enough to scan a barcode of a tag and do not insert it, so you have space to spray compressed air, for example.
Please note that it is okay if the debris falls from the carriage into the machine as we just need to remove it from the carriage, so it does not block the sensor.
If this still does not work please contact the MyFamily Support.