User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:72.0) Gecko/20100101 Firefox/72.0

Steps to reproduce:

1. Click button to add Numbered List
2. Type "item 1"
3. Press Enter and Tab
4. Type "item 1.1"
5. Press Enter and Shift+Tab
6. Type "item 2"
7. Press Enter and Tab
8. Type "item 2.2"
9. Press Enter and Shift+Tab
10. Type "item 3"
    11 Press Enter and Tab
11. Type "item 3.1"

Actual results:

Resulting List is:

1. item 1
   1. item 1.1
2. item 2
   1. item 2.1
3. item 3
   1. item 3.1

Expected results:

The third item should start with a 3.
There should be a right click menu to restart/rejoin list?

Whatever this web interface is formatted my intentionally incorrect formatted list into a correctly formatted one. Why cant Thunderbird do this? Just insult to injury.
Pay no mind to the "Actual results". Please reference the attached image.