Issue

• When ending a formatted text line with "!*\", "!**\" or "!***\" the wanted bold, italic or combination formatting isn't applied for backslash forced breaks.
• Escaping the exclamation mark doesn't help.
• Ending the line with two spaces instead of backslashes to add forced breaks works as expected.
• Issue is able to be replicated on https://spec.commonmark.org/dingus/

Test case (copy to the dingus)

***Failed to be bold and italic!***\
text

**Failed to be bold!**\
text

*Failed to be italic!*\
text