A set_clock_groups or a set_false_path between clocks <CLOCK_NAME1> and <CLOCK_NAME2> overrides a set_max_delay -datapath_only (see constraint position <#> in the Timing Constraints window in the Vivado IDE). It is not recommended to override a set_max_delay -datapath_only constraint. Replace the set_clock_groups or set_false_path between clocks with point-to-point set_false_path constraints.