Yes, looking more carefully again it is not Myriophyllum, I was wrong. It just doesn’t look like the Limnophila I have either, that looks more similar to Cabomba, not with single pointed leaves like that, but witht two opposite more rounded leaves, and not as firm. I wouldn‘t be totally surprised if they sold me a plant with the wrong id though.
This is actually really confusing as the two look quite similar. I noticed some time ago that I had two different species even though I bought them together. There are a lot of posts about the same question online, and from these I worked out that Cabomba has two leaves on each node, and they are finer, while Limnophila sessiliflora (also called Ambulia) have 3 arranged in a circular pattern at each node.
I found these two pictures, the first is Cabomba aquatica, the second is Limnophila sessiliflora.
To me it looks like those of the OP and Linda1234 are both L. Sessiliflora??