The fourth vaccine to receive approval in parts of Europe, the Novavax shot, hasn't had any reports that I could find of myocarditis.
Disclosure : I hold no position in NVAX, short sell or options. I also don't hold Takeda Pharmaceuticals, at either their US listed shares or CFDs of their Tokyo listing.
It took months for the first reports to come out about myocarditis from the J&J shot and several more for the mRNA variants. It'll take time to determine if it's safe or has other issues. Also there's fewer people taking it so that increases the time for side effects to show up.