Solr 5.5,6.6 spellchecker does not return the same response in single character query cases

When running the getting started example of solr 5.5 and 6.6 I noticed a peculiar behavior that occurs for single character queries under the /spell requestHandler

When searcher for a single term the response from solr does not have a spell check section compared to a two character query which does.

This seems to be independent from things like minPrefix (1 by default) and minQueryLength (4 by default).

I would expect that any number of character would return a spellcheck section.

I first came across this when trying to upgrade a solr plugin that had tests using single queries to assert suggestion counts.

I have included screenshots of the response.