Emoji and Emote Conflicts
The colon notation used by the Emoji One implementation conflicts with some of the Teams emotes. Specifically, no emoji that start with "s", "p", "o", "x", or "d" can be added from Emoji One as :S, :P, :O, :X, and :D all automatically convert to Teams emotes. This significantly reduces the number of emoji that can be used with the Emoji One implementation.
Gerald S commented
Yes, please include an option/setting to disable automatic emoji generation! 🙏🏼
There is a workaround, if you add \ to escape the colon, then continue typing the name of the emoji you want to use, then remove the \ and continue typing the emoji name. This verifies that the emoji are actually supported, and this is just an issue of the same shortcut being bound to two different actions.