That's really weird, can you play the template directly from its itch page, and check if you see this issue in it ?
This issue does not exist at all in the template nor itch or anywhere, I believe you are getting some frames skipped for some reason 🤔
What OS you are on ?
Are you getting the same issue with any other projects in gdevelop ?
Are you on gdevelop latest version ?
Running the game directly from its itch page on your browser still makes the same issue ? (what browser are you on ?)