1. The feed must move at the same moment
A window where the feed shows the old price is a mismatch, and it can trigger a review within hours.
2. Your break-even changes
New margin, new threshold. Judging campaigns against the old target after a price change is how good campaigns get cut.
3. Conversion rate moves, then the bidding reacts
Smart Bidding sees fewer or more conversions at the same spend and adjusts. Expect a short unsettled period and do not stack other changes on top of it.