If you're going to stick with that scale I'd write down the3 readings for a couple days, always weighing at the same point in your daily routine, and see if they change together.
I had a WW digital scale that worked great for years, then started acting up with different readings even after new batteries so I bought a new one after 2 days the new one got an error code and wouldn't weigh so I took it back got the same one and it's been great, it's a digital WW that does body fat, etc., not real expensive, anyway, it is very stable, so I'm finally just weighing myself once and moving on.
As mentioned above level can make a big difference, so check that out as suggested before buying a new scale that you'll have the same issues with.
Best of luck