Popping noise coming from rear brake drum

I suspect the grinding noise and the popping noise was the brakes. What happens is when you press the brakes they no longer drag but are fully applied so it dampens this noise.

https://www.2carpros.com/articles/vehicle-grinding-noise

The popping noise most likely was the shoe getting caught on the drum and it popped.

I would suggest removing and at least inspecting the rear brakes.

Here is a guide for this:

https://www.2carpros.com/articles/how-to-replace-rear-brake-shoes-and-drums

Plus below is the process from the manual. Please let us know if you have other questions and what happens when you inspect them. Thanks