It sounds like the issue could be a faulty fuel level sensor. The fuel level sending unit consists of a float and a resistor panel that the float attaches to. With the motion of the float the resistor sends signal to the gauge for the fuel level.
It is possible to have intermittent connection on that resistor, leading to the incorrect fuel level.
In order to access the level sensor, you will have to remove the fuel tank to get to the pump.
Another possibility is a faulty fuel level gauge itself, which is part of the gauge cluster.
I have attached diagrams below for your reference.
Let me know of any questions.
Images (Click to enlarge)
Saturday, May 14th, 2022 AT 7:44 PM