https://techcrunch.com/2018/08/14/ios-12-beta-7-pulled-after-reports-of-bugs-crashes/

Beta software always presents a risk going in. Companies usually recommend not installing it in primary devices for that very reason. For those who like to live on the edge, however, the latest beta of iOS 12 presented some very real issues.

Reports of buggy performance lag, freezes and crashes were pretty widespread for the seventh beta of the upcoming mobile operating system, causing some pundits to recommend skipping the install outright.