As described in AM003, the Calibrated Deskew feature is used to minimize clock skew on the global clock network.
- In Vivado 2021.1 and 2021.1.1 this is enabled by default
- In Vivado 2021.2 and 2021.2.1 this is disabled by default
If you are using the Clock Calibrated Deskew, the timing will have incorrect skew results.