Waiting is the right workaround. Think about it: she stays gold till next year. No point to re-upping till it's necessary. It's Delta's software that's wonky. Are you surprised? One reason GG (my SO) is happy to be earning Plat on her own after several years as a minimally traveling caregiver, relying on Diamond charity.

Plus I get another second choice.

Just think of it as an undocumented bug.

Good luck!