Shortcut Keys

Hello, I have a Redragon Karura 2 K502 RGB keyboard and as of today certain keys like G, M, alt, down key have started acting like shortcuts every time i press them. When i press them certain browsers open, certain strings get typed in or the alt button now just puts the pc in sleep...

I've just installed Asustek B550 motherboard after always using Intel mobos. The M4 boards do not appear to support a hot key to bring up the Boot Device Menu and instead I have to go into the bios each time. Is there a function key option I'm missing please? I occassionally boot from a usb...