2018 Toyota Highlander Braking Noises

Vehicle: 2018 Toyota Highlander SE

Issue: Grinding/Friction Rub and Fluid noise when braking

Details: On Feb 23, I replaced all 4 brake pads and front rotors. Ten days later, I noticed an intermittent grinding/friction sound when braking. Three days after that I started noticing a fluid sound occurring at the same time as the grinding. It’s now two months after doing the pads/rotors and it’s still doing it.

Things I can say I’ve been able to confirm:

Temperature is a factor. On the colder days, it would take 20-30min before I started to hear this. On a few 90 degree days, it happened within 10min.
Only happens at low speeds (under 15mph). Definitely more noticeable going down hill.
The fluid sound comes in at the few last second or two before coming to a complete stop. I do not hear the fluid any other time (not during turns, acceleration or any other braking)
The noises cannot be heard from outside the vehicle. The grinding/friction noise can be felt and heard within the car, and a front passenger can also feel it.
I’ve checked my ABS sensors to make sure they were clean and clear. I’ve topped off coolant (which was near full anyway). I’ve check the pads and rotors – doesn’t appear anything is wrong there.
Help, please. I’m about to lose my mind!