ADS analyzes performance from the last recorded bid change, (or when a new keyword is added) for up to 90 days prior, for ALL of your campaign keywords, every 24 hours. When you view a keyword on the Bids tab, the initial suggestions are the result of the last bid change listed in the Last Update column, through to the day they are viewed, disregarding the last three days. Amazon frequently updates and/or invalidates PPC data within the first 72 hours of reporting it, therefore ADS does not include this data in its analysis.
When you make a bid change in ADS (or within Seller Central), ADS reviews a minimum of seven days of data before making a suggestion for that keyword. So a bid change made today will not appear in Suggestions again until another 10 days pass. These 10 days include seven days of review data plus the most recent three days that are, then, disregarded.