Hello @MisterPi
The two rules target different kinds of complexity: Cyclomatic and Cognitive.
To understand the difference, I suggest you to have a look at the different resources available discussing the topic:
In just a few words:
Cyclomatic Complexity is about testability - what’s your minimum number of unit tests to exercise all the code? Cognitive Complexity is about understandability.
Today, only the rule using Cognitive Complexity is enabled by default, as we believe it is best suited for the purpose of having clean code.
Still, the rule using Cyclomatic Complexity is available if you need this measure.
Hope it clarifies the situation.
Best,
Quentin