Hello
There is issue with first time (or after long inactivity) iOS simulator in case when it ask for password. VS do not wait for authority finish and exit running app with error: has exited with code -1 (0xffffffff).
App in simulator hang on startup logo/screen and cannot be removed from task list. Only simulator close or reboot helps.
b.r.
Hmm. the iOS Simulator asks for a password? I’ve never been or heard of that.
it’s mac protection. Is same when You trying to install any software, then it ask for password. Same password as for login.
Here is explained: https://support.apple.com/en-us/HT201760
[EDIT] To disable it I found and used:
sudo /usr/sbin/DevToolsSecurity --enable
b.r.
Hmm. i’ve never had that happen for the iOS Simulator though. it just launches, without needing elevations for me.
Probably it will not happen, when You do not use login to system (autologin enabled) 
Btw. fire do wait for auth.
b.r.