Meaning of ‘Jump in’ Phrasal Verb in English

During the debate, he jumped in with a strong argument.

She likes to jump in and help when there's a problem at work.

Don't be afraid to jump in if you have something important to say.

He often jumps in to mediate when there's a disagreement among his friends.

If you have any ideas for the project, feel free to jump in and share them.

When they started discussing the movie, I couldn't resist and jumped in with my favorite scene.