Hi,
It seems that the element "separation line" in the description section of a card is broken on MacOS 11.7.10 while still working as expected on Android.
1. On MacOS, open Trello and create a new card
2. Click "Insert elements" (+ Symbol) and scroll down the menu
Expected: "Separation line" available.
Actual: "Separation line" not available.
Furthermore:
Typing "___" to create a separation line used to work on Mac and Android, but also not anymore on Mac. Instead, typing "___" on Mac and opening the same card on Android reveals that MacOS Trello writes "\_\__".