This answer record provides details about the behavior of the 7 series GTP IBERT core when the QUAD reset is asserted by the user. This behavior only affects the core available in version 14.2.
When the QUAD reset button is pressed for a given channel, the appropriate PLL for the QUAD is reset in addition to the channel. In some cases, other channels may be dependent upon the same PLL. In that specific case, pressing the QUAD reset may cause other channel links to go down.
This is a known issue in 14.2 and will be fixed in 14.3. If you see behavior where hitting the QUAD reset causes other channel links to drop, hitting the TX Reset and then the RX reset will restore the link status of the affected channels.