  Under the U.S. High Luminosity LHC Accelerator Upgrade Project (HL-LHC AUP),
the 150 mm bore, high-field Nb3Sn low-\b{eta} MQXFA quadrupole magnets are
being fabricated, assembled and tested, in the context of the CERN
Hi-Luminosity LHC (HL-LHC) upgrade. These magnets have 4.2 m magnetic length
and 4.56 m long iron yoke. To date, eight MQXFA magnets have been tested. One
of the magnets additionally underwent a successful endurance test with 40
triggered quenches, and two magnets did not perform as expected. This work
summarizes for the first time the available strain gauge data from eight
identical Nb3Sn MQXFA tested magnets, focusing on the endurance test, and on a
possible cause of underperformance of the two magnets that did not pass the
vertical test. We applied methods to prevent this from happening in future
MQXFA magnets, which shown to be effective for last two tested magnets.
