I think that Android is much faster to life than connected devices, be it a SIMcard of WiFi via hotspot.
It is the same for USB. Android is long up and awake, and only then the USB devices are mounted or reactivated again, meaning that media players running from external memory like SD-card or SSD, don't have access at the moment Android and the media player are already up and the mediaplayer tries to continue where it was.
I think it is the same for a SIM-card of WiFi hotspot. This is already the case since early models. When you have an online navigation app at startup, it has no wifi at the beginning when Android and Google Maps (or another) are already running. I have that with Google Maps and Magic Earth in my setup with hotspot as well, and I am used to it since 2015 (5th unit now). I don't know why Waze hangs, as Magic Earth and Google Maps do not hang but react with some delay.