After running IPS on Red interface for a few hours I noticed that some sites stopped working, for example these two:

https://www.ipfire.org/

https://en.wikipedia.org/wiki/Inverse-square_law

Found that disabling IPS on the Red interface returned normal access to the two sites listed. Then enabled Red again and access still worked but did fail again after a while. Did not try and measure for how long it takes to fail though but it's a number of minutes.

Tried disabling all Rulesets and that did not restore normal access.

Regards

Wayne