I think the vaccines work if you have a healthy immune system. Otherwise, you can get COVID which can cause myocarditis.
If by "work" you mean allow you to still get, spread, and die from covid, then yeah they work just fine.
You've got your head up your own ass. The vaccines cause myocarditis because of the spike proteins in the tissue of the heart which cause the immune system to attack the heart muscle producing inflammation which is what myocarditis is...inflammation of the heart muscle. It also causes pericarditis which is inflammation of the sack around the heart by the same mechanism.