Design Flaw. The internal clock should have its own battery which will stay charged much longer than the main power source.
One of those things for the next generation.
Perhaps no one thought of it at the time (or didn’t think it would be a concern) because it was a concept model. Optimistically, Ingenuity would last 5 flights over one month.
Passing the one year mark and 28 flights, the team really gets to exercise some ingenuity in keeping it going, so the issues provide a beneficial learning experience no matter what.
Besides, at this point Ginny might have quite a fan club.