OP, ring the school. I have a list of about 300 students I am responsible for chasing. I am only just reaching the end of that list now, 2 weeks in. When I call them, many of the parents believe that there is little work set, or it isn't being marked, or we're not checking up on them. There is, it is, and we are. On top of those phone calls, I've been sending messages to the kids daily. Unless you are checking their work personally, don't take their word for what is, and is not, being set.
Some children unfortunately go to great lengths to hide what they should be doing from parents and do as little as possible, I am afraid. I have had several children who yes, have been accessing our online learning platform daily. But instead of doing the work set on simultaneous equations, they have been doing 2 and 3 times tables. So they LOOK like they are doing work, but they're really not. They are "forgetting" passwords. They are reading messages but not acting on them. They are coming up with all kinds of excuses, such as "I don't have Word installed" - no, but you don't need it to access a website, do you?
In school, some of these children would, I am afraid, have to be constantly nagged to get their books out of their bags. To open them. To put down their title and date. To copy the notes from the board. Quite aside from actually doing any work. We know the battle you are fighting. We fight it with many, many children, hour after hour. This behaviour is not new. Getting them to do anything can be very, very hard work and we teachers often feel that we are putting in hugely more effort to get them to do it than it is taking them to actually do it.
The most important lesson you can learn in school is not maths. It isn't how to identify fronted bloody adverbials. It's how to work hard and persevere. We can try to inspire them, even when, especially when, we know they are bored. But we can't teach a work ethic without your help.
If you really, really can't get them to do any school work, this is my suggestion. Give them the option of doing school work or pulling up weeds, or cleaning the bathroom. Don't make it the option of doing work, or having screen timey fun. The real world doesn't offer that choice to any of us and you won't be doing them (or us teachers) any favours making them think it does.