In the following figure, a create_generated_clock constraint was
defined on the MMCM instance pin CLKOUT0, but doesn't
match the auto-derived waveform generated by Vivado
from the MMCM attribute settings.
To just rename the auto-derived clock, use the following constraint right after the master clock definition in your constraint files:
create_generated_clock -name clkName [get_pins clk_gen_i0/clk_core_i0/inst/mmcme3_adv_inst/CLKOUT0]Figure 1. Invalid Clock Waveform on Clock Modifying Block