You can observe there are setup timing violations in below clock domain inside the Altera® XAUI PHY IP.
Launch clock:
phy_mgmt_clk
Latch clock: xaui_phy0|xaui_phy_plda_inst|xaui_phy|hxaui_0|use_device_family_siv_sv.hxaui_alt4gxb| hxaui_alt4gxb_alt4gxb_dksa_component|central_clk_div0|coreclkout
The failing paths are due to one clock domain being synchronizing with another clock domain and there are 2 synchronizer registers for each failing path.
To workaround this issue, you are safe to ignore the above different clock domain setup timing violation inside Altera XAUI PHY IP.
This problem will be fixed in a future version of the Quartus® II software.