Hi,
In one Cubase version, this bug was highly present. Once you stored the preset in that version, the name of the preset has been corrupted and you cannot load this preset anymore (in any Cubase version). This has been fixed (at least the most obvious case). Since then, the same issue appears time to time to some users even with newer Cubase version and with a new presets. But unfortunately, there is no clear step-by-step reproduction available (with the new preset, made from scratch in the current versions), so its hard (impossible) to catch it.