Assistive touch - number of icons bug

Every time there is an iOS update, the number of icons on assistive touch gets reset to 7 altering the layout of my personalised 5 icon menu, this is inconvenient as I use 5 icons. In an event of iOS update I have to go into menu and manually change it back to 5. I don't imagine iOS update needs to default it to 7 icons, rather it could just leave it as set by the user.