The plant has interveinal and marginal chlorosis, so it appears to be a nutrient uptake problem and it's mobilizing mobile nutrients from older growth to support new growth. This can be related to things like your media choice, poor drainage/compaction, root issues, watering and fertilization habits, etc. If you post about your transplant, e.g., what media you transplanted into, and your watering and fertilizing practices that would help people help. There are many reasons this can happen and it can take a fair amount of information to determine the cause. You don't appear to be in any emergency though, so that's good.