When using the UHD-SDI GT core in Vivado 2019.2 with "Enable PICXO ports" enabled, switching between FRACXO and PICXO has no impact on the ports of the IP.
On GTY, the ports enabled are always the ports used for FRACXO:
On GTX, the port enabled is always the port used for PICXO:
This is a known issue in Vivado 2019.2, where switching the option between PIXCO and FRACXO has no impact.
This issue is planned to be fixed in a future release.