We are still using PHP 7.3. A recent upgrade to latest PHP 7.3.29 included an upgrade of the tideways extension from v5.0.2 to v5.0.4. This was a bad decision. Our PHP-FPM was much more busy in terms of CPU usage. Downgrading to tideways v5.0.2 fixed our performance issue. Please note that we did not on profiling using the "enable" function.
I got the impression that the profiler was always on because of the update. Does this affect only PHP 7.3, or only PHP 8.x?