very slugish keybord on iphone & ipad

First of all this has been effecting all my apple devises my iphone 6 plus, my iphone 15 pro max , my old ipad pro 2017 and my ipad pro 2020 but has become imposible to use with my new iphone 15 pro max. it first started when texting wrong key and space bar needing 2-3 taps after every word. and the curser very unstable while typing look up and its jumped to the middle of a word the paragraph above or below. it seems to not have the power to keep up and I have closed every app but itdont help. there are short times that it improves but not very long there has always been a problem with moving the curser to a line above or below to correct a word or trying to copy and paste the screen is very unresponsive to taping in any app. And I have questioned my own sanity and typing skills. but this is a huge problem