Totally correct. This isn’t anything to do with Allegris, it’s just LH revenue management’s sketchy behaviour giving worse availability to existing tickets compared to new bookings. Often your better cancelling and rebooking.

This is actually the biggest issue I take with LH Group as a whole, it’s so misleading selling “Full Flex” tickets when they aren’t actually flexible at all. Often it’ll even show F0 (forget A), even when the cabin is empty on different days.