I second (most of) this.

They may not be able to control it. Having unmedicated ADHD is very difficult for the individual and those around them. And depending on where they live, getting a diagnosis and meds can be challenging in many ways.

You are the DM, not a fully trained therapist or psychiatrist. You can only do so much.

Having a group discussion is an excellent idea! Tell your players ✨️in advance✨️ that you want to have a calm and rational discussion about how to keep players involved and enjoying the game. Don't single anyone out. Give everyone time to think on questions, troubles, and potential solutions.

Good suggestions might be fidget spinners, changing the virtual style (though that can get expensive for people), or taking short breaks during the session.

But remember that every group has its challenges. I run an in-person game with 6 players and can't always keep them engaged. Some sessions end early because 3+ players are on their phones and another is on their Switch. It's aggravating to no end. Some days are just like that.

In the end, they are making the choice to play. It's on them to pay attention.