Squeaking noise from a wheel/breaks

[devg117]

I bought a diesel RAV 4 60k miles on the clock in September. In October I noticed after a long journey that I was getting a metal grinding noise. Took it to my local Toyota garage and the reason was the previous owner had fitted non genuine break pads and disk which caused the calliper sliding pins to seize on all pads and disks. All of them have been replaced with genuine parts. The grinding noise went away but after couple of weeks I started to get the squeaking noise after a month. They’ve loosened the breaks in November and it went away at the time but the noise is back again. As you can see and hear from the video attached, the noise is coming from the rear passenger side wheel/ breaks only when doing around 5 miles per hour. Please kindly advise what this could be? Many thanks.