@Infojoe Unfortunately my test environment where I would normally work on these things hasn’t been behaving nicely.
Luckily, however, a fellow developer @rodluz was able to narrow the “what” and I believe I have fixed it.
The issue at least based on what was found:
PHP 8.1 deprecated the FILTER_SANITIZE_STRING feature and I replaced it with FILTER_SANITIZE_SPECIAL_CHARS or something alike to it.
This was the expected change at the time, but forgot that special characters may show up in Session variables (among other variables)
So say an & would get created, well FILTER_SANITIZE_SPECIAL_CHARS would encode & to & which would then see the & again and perform the same trick over and over and over in a recursive loop.
This is what was causing the CPU spikes, my apologies for that oversite. This has been addressed within the latest dev-branch if anyone would like to kick the tires?
Thank you!