After the Apple 15" MacBook Pro (2018) was left on overnight, in the morning we tried to turn on the Mac and found it was in a dead battery state. We didn't have the Apple 87W USB-C Power Adapter that came with the Mac but instead used the Apple 61W USB-C Power Adapter.
It was also confusing for the user on what the different symbols on the display meant especially since there is already a Apple charger connected.
The display also sometimes became dark.
In general, when connected to a proper AC charger, the Apple 15" MacBook Pro (2018) should be able to run in any battery state. 60W USB PD chargers are very common for notebook PC charging so it's surprising that it would take so long for the Apple 15" MacBook Pro (2018) to turn on using Apple's own 61W USB-C Power Adapter.