I'm sorry but I am using the current FOCL website.
As an example, I've selected at random cruise S2409 Wildlife and Culture of the Scenic Scottish Isles on the Borealis sailing from Southampton on the 7 May 2024. Going to the booking options on this cruise the cabin catagories offered are Suite, Terrace, Ocean and Interior. There is no specific Balcony catagory. [Athough the Suites on offer are described as having a private balcony]. The Terace cabins are described as offering access to the Promenade deck via sliding doors - there is no mention of a balcony.
Perhaps you could check this cruise and see if you can see the same as I've described? If not perhaps your computer is holding an old copy of the FOCL website and, if this is the case you would need to delete cookies etc.