Risk of myocarditis following sequential COVID-19 vaccinations by age and sex https://www.medrxiv.org/content/10.1101/2021.12.23.21268276v1.full.pdf In summary, the risk of hospital admission or death from myocarditis is greater following COVID-19 infection than following vaccination and remains modest following sequential doses of mRNA vaccine including a third booster dose of BNT162b in the overall population. However, the risk of myocarditis following vaccination is consistently higher in younger males, particularly following a second dose of RNA mRNA-1273 vaccine.
I am well aware the MedRxiv site is for pre-prints only and not peer-reviewed studies. However, I doubt these pre-prints are investigated or even allowed to be in the current censorship.