Car starts after jump but battery won’t hold charge

[shanonia]

Not sure. Some batteries cannot hold a charge. If you remove the battery to charge it, you are decomplicating the situation. See if it takes and holds a charge, without any connection to the car. (You may have to reset radio memory, etc. Check owners manual about that. In some cars it is a big hassle to remove and install a battery unless you have special equipment, so I don’t want to suggest some step that might add to the mysteries.)