2007 prius repeated wheel bearing failure

Has anyone else experience repeated wheel bearing failure almost imediatley? I just bought my prius used and knew it needed wheel bearings. Replaced those and the replacements failed imediatley. Repeat that 2 more times and thats where i am now. I kept thinking it was cheap parts but its happened enough for me to think its something else. Before the replacement bearings would separate causing my bearing to pull out around corners making my rotor hit my caliper bracket making grinding noise, but no hum. Now i have only one wheel grinding lightly around corners and loud hum in both. Ive done bearings multiple times in the past on other cars and no problems. Im wondering if there is anything i am missing or anything else could cause this or is it bad parts again?