Tempress II, Noise in shower

[Jay3Boyz]

One night my wife was showering my son and then there was a loud bang and shower head pressure went down and the bottom spout water was also flowing.

I was told it could be the cartridge behind the handle. I opened up and saw Tempress II so i searched and found the cartridge. Replaced and now there is a weird sound that can last 2-3 minutes and it stops. It is somewhat loud. Please see video. I also replaced the push pull diverter and still has same sound but now the spout drips a bit when shower head is on which is better but not a lot of pressure before the problem started. I am not a plumber and any help would be appreciated.

See shower noise video

 

[Smooky]

There are two screws missing in the cover plate. That might cause a noise. Between the shower hose and where the pipe comes out of the wall there are two parts. What are they? (One looks like a swing check?) Is the other one a filter, diverter or what?