The float? Is it the indicator?

Guys, my car's tank takes 50 liters. My tank was almost full, it was on the 7th tooth out of 8 on the gauge. Anyway, I filled it because the fuel would be expensive, it took another 7 liters, but the indicator did not go up from the 7th tooth. I went the way I always go and spend about 7 liters. 6. He came to the tooth. In other words, while there were 7 teeth of fuel in the tank, it was always 1 tooth down. Then I filled the tank again in a different place. The indicator remaining in the last 6th tooth could not go up again. Again, I did the way I spent 7 liters. It came to the 5th tooth. So when the fuel gauge comes down, it counts. It doesn't go up. Now is the problem with the indicator or the float as well? Has anyone ever had such a problem?

I disassembled and cleaned the tank today, I emptied it completely. It took 78 lt. It takes 4 5 lt. First it showed full full, then 1 line fell from the fuller and then it got better again. I think the electronic part of the samandra is dirty because we are using it tomorrow or six months.

Since the fuel pump was broken in my previous vehicle, I would always drive on full and half in order not to break down in this vehicle. But no matter what I do, if it will break, it will break.