I made a couple of tests by Xubuntu Core 20.04 live USB (downloaded from https://unit193.net/xubuntu/core/). First time was by default settings i.e. 'lock screen when system is going to sleep' checked - I think that is not a good default setting for live - and the other time when it was not checked. Both times it did not suspend. The former did blank screen immediately, the other one after delay of several seconds. No keyboard activity did have an effect so I had to use power button.
I made a couple of tests by Xubuntu Core 20.04 live USB (downloaded from https:/ /unit193. net/xubuntu/ core/). First time was by default settings i.e. 'lock screen when system is going to sleep' checked - I think that is not a good default setting for live - and the other time when it was not checked. Both times it did not suspend. The former did blank screen immediately, the other one after delay of several seconds. No keyboard activity did have an effect so I had to use power button.