10.11.6 startup menu not seeing mojave

[iMore Question]

Hi, I updated from 10.11.6 to Mojave and everything is working, but when I'm back in the old OS 10.11.6 looking for Mojave in the startup menu it's not showing.

It does show when restarting holding the option key, and starts normally.

 

[Just_Me_D]

Can I assume you're dual booting your Mac?