Summary
Emojis picked from the Android or iOS system keyboards are not displayed properly on Chrome or Windows client.
Steps to reproduce
Mattermost server 5.17.1 using mariaDB 10.4 on Debian 10, with utf8mb4 encoding.
Post a message from the Android Mattermost mobile app, containing an emoji picked from the Android system keyboard (not the Mattermost emoji picker). Display the message on Chrome or Windows client and notice that the emoji is not displayed properly.
Custom emojis enabled.
Expected behavior
The emoji should be either converted to a “Mattermost-compatible” emoji or displayed like Firefox is doing.
Note that emojis picked from Mattermost are displayed just fine and emojis “manually typed” (for ex: :p) are properly displayed everywhere.
Observed behavior
Windows client / Chrome above
Firefox below