Sync and async clocks, fitter, ...

Two clocks are synchronous if the relative position of their edges is known or can be calculated (with some uncertainty); they do not need to be edge aligned nor exact.

If this condition is met, then the TimeQuest can and will analyze the timing of any path between those two clocks.

If the relative position of the clocks' edges can't be determined, then the clocks are asynchronous.

In that case, you need to use asynchronous clock domain crossing techniques to cross between the clock domains.

And you need to use set_clock_groups/set_false_paths to tell TimeQuest not to try and analyse paths between those two clocks, as any analysis would be non-sense.

Which brings us to why you don't get any timing violation reports: by setting the clocks as asynchronous, you told TimeQuest not to analyze those paths.