Help with rslogix copy

I am working on a program where I have 4 tanks each with the potential for different blends.

I have written logic to interact with wonderware where the supervisor will dictate what blends are in the tank so they will type in this blend code. For the valve to open to fill into the tank I have an input string that will need to match before the valve opens. Once the tank is full and the valve closes I am using the COP to copy a blank blend code into the original blendcode which should clear the inputed blend number and leave the input block blank. This works for a couple of tanks but not all. Could someone take a look at the logic picture attached and see where I am missing the boat. Keep in mind that I am using another rung in logic to match to strings (EQU) which sets the bit BlendCodeOK bit to allow the valve to open. These valves are fail open so the output is off when in the open position.

Thanks RM

if your logic is repetitive for all tanks then maybe it a case sensitive issue. Where the supervisor is not typing in your string the same way entered in program. The ASCII value of letters is different for upper case vs. lower case. This would cause the = instruction not to work. Maybe another solution would be to give them a drop down list to choose from for your blend selection. That way you could control the entry.

I verified the string match and I have no problems with that. The problem I am having is the COP function and resetting the code to blank after the valve closes.
I am using the valve.closecmd then going through a one shot I am coping a "blankcode" tagname set up as a string to copy to my blendcode tag. On some this is working fine but not all. I have check and verified typos etc.

Re-using one-shot bits?
Really, can't tell anything from that picture.

Instead of a one shot try something like this.

If tank full and valve closed and Blendcode <> Blankcode then copy Blankcode to Blendcode

This rung should stay true until Blend Code is removed.

RD could be on to something with one shots being duplicated. Easy to do when you copy and paste repetitive logic. I can see you have 2 warnings on the verification screen.