I solved this as detailed here: (you have to save a keymap and set the active keymap to "positional (user)")...

https://retropie.org.uk/forum/topic/25350/c64-vice-not-saving-hotkeys?_=1586028149192

@RandoCalrisian sorry. I wish I wish I knew more about the firmware. My IPAC4 device is an older version that uses a PS/2 to USB converter and it does not get recognized as a game pad at all. It's my understanding that this issue affects only the newer versions of these devices. I hate to send people to Andy for support every time, but as far as I know, he has been the only source cited by people who have obtained the replacement firmware. However, perhaps he has now incorporated it into the utility available online.