Scared jumpy fish

[XG332]

My gourami in my tank have become very scared and jumpy.
I've done a water test and results show ph, nitrite and ammonia as fine but nitrate is very very high.

So I have been changing 20% water every day for the last 3 days and also vacuuming the substrate thouraghly. I've also added nitrate removal media into the filter.

Tested the water again today and I'm not seeing the level decrease.
Is there anything else I can try?