Fuel level reading wrong?

My fuel level rose from 3/4 to almost full while driving for about 40 minutes. I did ask a previous question about a gurgling/bubbling sound coming from the gas tank and was told to replace the fuel pump assembly so I did which solved the sound issue and during that time I pulled 5 gallons of gas from the tank with around 2 to 3 gallons left in it before installing the new assembly into the tank and putting everything back onto the car and put that same 5 gallons back into the car which is when the gauge went to 3/4. Drove to the next town over thats when the fuel level started going up and fuel range went from 190 to 230. So stopped at the gas station and fuel level was reading almost full at the time and was only able to put a little over 3 gallons in it then the level went back to 3/4 after starting the vehicle.

Sorry for the long and possibly confusing description but just wondering if I got a bad fuel pump assembly or is there something else I should be looking at or checking.