Emojis appear just for a second, then disappear

[MBAC62]

Thunderbird 78.10.0 (32-Bit)

When I insert some of the emojis, everything works fine. Others just appear for a split second - then there is just an error symbol. What can I do?

[mganss]

Strange. My guess is that it might be because of a network issue or perhaps there is something that's blocking the download of images (antivirus?).

To verify, you can try and open developer tools (from the main menu or press Ctrl+Shift+I) and select the network tab. Now insert some emojis and observe if there are any failing requests. Each emoji should result in a network request for the corresponding image.