My phone is plugged into my computer via USB - it is charging, but I do not see any options to change the USB connection mode in the notifications drawer. I have seen and used these options in the past, but it is not showing now for some reason. They looked similar to this - https://cdn.arstechnica.net/wp-content/uploads/2015/05/usb2.png.
For context, I had the phone in 'USB Debugging' mode earlier on, but I've since turned it off -
adb devices was not listing my phone anyway, although that also has worked in the past.
I am running Android 8.1 on a Nexus 5X.