backtick doesn't autoformat code block for single character in pull request comment

My use case was formatting an index value of 1 on a pull request. Further testing shows other examples such as a and ? don't.

However, values such as a1, 1a, ?a work as expected. This leads me to believe it's a problem with single character values.

Current workaround is inserting a code block through the editor menu and typing in my desired value.