Participants freezing

I'm a tutor and I've been using Zoom for the past 4 years. Lately I encountered a problem that I've never ever encountered before. 2 of my students are constantly freezing and leaving the meeting (exactly like it would happen when someone has a connection issue). I do not experience this with ANY of my other students. JUST with these 2 specifically. They have other online classes as well and they don't experience this problem with any other tutor. JUST with me. They've tried logging in from different devices, but it's still the same. I've even created a new account, but it still doesn’t work. What is the problem and how can I fix this?