Misfires after disconnecting the battery

That is common on many newer vehicles. It is because the engine computer starts at a baseline that assumes new sensors and no wear. As it ages and sensors and parts wear the computer learns the "new" normal and keeps things running smooth.

When you disconnect the battery all of that information is erased and the computer needs to re-learn everything all over, from idle control to compensation for wear.

Basically you try real hard to keep battery voltage intact. Either do not disconnect the battery unless it is very necessary or be prepared to have the system relearn the controls. As for the reconnect multiple times, that is a waste of time as once the data is erased from the memory the only recourse is for it to relearn.

I use a jump box connected to the vehicle to change out batteries just to keep from clearing the memory.

Does not change the fact that it is common on many makes for the ECM to clear the learned memory when the battery is disconnected. I see it on many vehicles from Audi, BMW, VW, Chrysler, Ford, GM, Toyota, Mercedes, Honda, Lexus. It depends entirely on how they store the learned data. On some they have a small back-up battery or a large capacitor that can hold the memory for an hour or so. On others it clears almost instantly. Then the PCM loads default values that may or may not allow the engine to idle or even run depending on how it has been maintained and how worn it is.

As an example take a dirty throttle body. The plate can no longer close properly because of carbon build up. The PCM learned how to keep it idling correctly by adding more air through the IACV or by holding the plate farther open to maintain the correct speed. Now you disconnect the battery. The PCM is wiped and loads the default idle setting. That setting however no longer functions because of the build up inside the throttle bore or IACV. So the engine will not idle, it might buck and misfire or stall because it is not getting proper fuel.
On some vehicles you use a scan tool to trigger a re-learn, just the same as triggering a KAM reset if you replaced a cam or crank sensor.
On others you perform the reset by just driving the vehicle around.

You are welcome. I can also tell you it will get worse as the companies add more and more electronics to even the low end vehicles. They cry because they need to remove weight from the cars to get better mileage, then turn around and add four new modules and one hundred pounds of wire to make the turn signals work. Or the stupid idea to put the fuse panels in the rear of the vehicle then running wires from the front mounted battery back to it so it can power the headlights!
Plus auto makers are really trying to push DIYers and even independents from being able to repair the vehicles at all.