Shoulder cracks or clicks are not from the shoulder muscles.
Rather, usually the tendons or a Labral tear are the causes for such noises.
Even if the cracks are not accompanied with pain you should, at the very least, have a competent personal trainer (or even a physical therapist) work with you on your shoulder training.
- I have my clients do their shoulder presses, shoulder flies etc. at a bit of an anterior angle (slightly in front of them) as suggested by Jeff Cavaliere, PT. This generally gets rid of the clicking and even discomfort.
If you are feeling discomfort/pain with the cracking you should see your medical care provider about it to rule out any injuries.