I think it is still possible that the issues is a the bottom.
if there is not enough force at the bottom to keep the battery in its place at the connector it will cause bad connection.
in your case , it seems like the battery was so low, the connectors pins were not inside the female side of the battery and made the damage to the plastic.
connector is probably suppose to be inserted 4-5mm, so this means the battery was too low for 4-5 mm.
i'm supprised canyon is still selling without solving , at least a temp solution.
good luck with trying to sort this out
if there is not enough force at the bottom to keep the battery in its place at the connector it will cause bad connection.
in your case , it seems like the battery was so low, the connectors pins were not inside the female side of the battery and made the damage to the plastic.
connector is probably suppose to be inserted 4-5mm, so this means the battery was too low for 4-5 mm.
i'm supprised canyon is still selling without solving , at least a temp solution.
good luck with trying to sort this out