Settings -> Desktop & Dock -> Hot corners -> set one to "Disable Screen Saver"
Then just shove your cursor into that corner whenever you want to leave your computer without it sleeping
Type `caffeinate` into the terminal, your mac will stay awake until you ctrl+c it
I remember trying a bunch until finding some combination that worked, and looking around it sounds like it's still a common issue:
https://apple.stackexchange.com/questions/475477/caffeinate-...
/Library/LaunchDaemons/ze.caffeinate.plist <?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd"> <plist version="1.0"> <dict> <key>Label</key> <string>ze.caffeinate</string> <key>ProgramArguments</key> <array> <string>/usr/bin/caffeinate</string> <string>-s</string> </array> <key>KeepAlive</key> <true/> </dict> </plist>