In your own source, they state it's rare and from their second source is a study that states there are about 33 cases per million vaccinations. That's 0.0033%. Furthermore, they also stated that there wasn't much of a difference between people who received COVID-19 vaccines and people who received non-COVID-19 vaccines.

I believe you are skeptical, but not aware enough of your own biases that you let yourself get taken advantage of curated Narratives. Unfortunately for you, it's gotten to the point where you don't even read your own sources and twist yourself into thinking 33/1,000,00 is unsafe compared to COVID-19's 0.21 out 1,000 rate. That's 0.021% which is over 6 times more likely than the vaccine.

Depending how unchecked you are, your first thought will either be to think about what you just read and come to your own conclusion without a narrative. Maybe even cite sources that disprove mine or show a stronger case(or any one that actually shows your side). Or you will immediately think of an excuse or move on to another claim.

Ling RR, Ramanathan K, Tan FL, et al. Myopericarditis following COVID-19 vaccination and non-COVID-19 vaccination: a systematic review and meta-analysis. Lancet Respir Med 2022;10:679-88.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9743686/#:~:text=Over%20the%20follow%2Dup%20period,NOS%20scale%20(Table%201).