Definitely need a new chair if you're sticking with a high chair. Alternatively, you can get a small table/ chair for her to eat at instead. One she can sit at safely and get up/down when she pleases.
My baby does this, too, and we got a lap tray from Ikea, and he sits on the floor to eat. We've all transitioned to the coffee table for meals so that we're sitting together. No TV! It's just easiest for us,as he is SO BUSY and likes to stand while he eats.
Our high chair has an adjustable tray that slides in really close to her so she's basically trapped in and can't do this. We were having the same issue but she HATES being strapped in so we actually just bought this one.
I wouldn’t put her in this chair even one more time. A fall can happen quickly and could be very serious
yah you need a new high chair because that’s the reason they come with straps 🙃 that’s a fall and choking hazard not having them safely seated and strapped in