Suspected periodic performance regression after upgrading MariaDB from 10.6.15 to 11.4.7

Report and question regarding how to approach suspected significant periodic performance regression after upgrading MariaDB from 10.6.15 to 11.4.7.

We have many reads and somewhat less writes on a beefy master MariaDB server​, like below.

The queries are optimized so that there are no slow queries over 1 second, and we have automated alerts for any queries that are over 1 second.

After upgrading MariaDB from 10.6.15 to 11.4.7, we suspect a significant performance regression.
Suddenly we get short time periods where performance drops then is normalized.
The type of queries we sent during time periods are spread out and should not cause periodic problems.
Before MariaDB master server upgrade our app profile shows very stable MariaDB performance which are the red stripes below:

After upgrade our app profile shows unstable MariaDB performance which are the red stripes below:​

Currently as I can't find anything wrong with our app or queries, I am considering downgrading our MariaDB back which will be a huge task.
Before I do so, any suggestions on how to approach major performance regression after upgrading MariaDB from 10.6.15 to 11.4.7 like above?

If MariaDB dev team is interested I would be willing to give direct access to the server through remote screen.

Thank you.
Have a nice day.