Entirely predictable and should have been managed.
Carclo, or others, don’t have machines and moulds standing idle just waiting for orders, they predict demand (probably minimal) for these optics, maybe run a small batch once a year, in a day, to supply distributors who have committed to purchase them.
Moulds also wear out, and decisions are taken whether to bother re-making them or just obsolete the product.
Customers with a good relationship are given notice of these decisions, and offered e.g. “last time buys” to stock up.
Not saying this is the case here, but it wouldn’t surprise me. Carclo could explain what’s going on, if contacted properly.
Meanwhile their machines are dedicated to their serious business, e.g. streetlights, factory and warehouse luminaires etc. R+D, that brings in the big money.
If they have a big order for these keeping them busy, the esoteric little old small margin small volume things won’t be considered.