iPhone Calendar

Thank you very much for your reply and tips! When I say to iPhone calendar I’m referring to the calendar that automatically comes installed on the iPhone upon purchase. This calendar uses my gmail account. It is set to sync all events. Nothing changed on my end, as it’s set up just like is always been from the time of purchase. This is how I’ve set all my iPhones. Nothing has changed with this phone other than doing an iOS update which it’s been since that update that the calendar has stopped showing results when doing specific searched events. There has been a few iOS updates since that update but the problem still persists. Also I use these exact same settings on the following devices - iPad Air (current version), iPad (current version), iPhone 6s Plus, 8 Plus, SE, 12, 12 Pro, 13 Pro Max, and 14 Pro Max - which none of these devices have this issue. It is only the iPhone 12 Pro Max this is happening to since doing the iOS 15 update. I have several family members and friends who also have the 12 Pro Max who all as well are having this exact same issue with the calendar search results. Thank you again for your help!