The number you add/subtract/multiply a counter by resets back to 0 when switching what operation you want to perform on the counter, rather than simply storing the value. For example, if you have it set to add 1 to the counter, then change the add to subtract, the subtract value gets set back to 0.
This only happens if you set the value and change the add/subtract/multiply setting in a single “session” of opening the connections menu; if you change one setting, close the menu, reopen it, and change another setting, there is no issue.