TeamCity Statistic Definition: MaxTimeToFixTest

I'm using the TeamCity REST API to access build statistics.  One of the returned statistics is "MaxTimeToFixTest".  On the surface the statistic appears to be self explanatory, but I'm not seeing any information in the documentation about how exactly it's calculated/what it is actually measuring.

One of the reasons why I'm asking is because sometimes when a build fails it includes a value in that field.  Sometimes when a build fails, it does not include a value in that field.  Also, I also have cases where two subsequent builds fail, and they both contain a value in MaxtimeToFixTest.  Sometimes when two subsequent builds fail, only the first failure contains a value.

Can you please help me understand what MaxTimeToFixTest is actually measuring, when it gets a value, and when it doesn't?

We're running TeamCity Enterprise 2017.2.3 build 51047.

The REST endpoint I'm querying is: https://SERVER/httpAuth/app/rest/builds?locator=buildType:BUILDTYPE,count:5000&fields=build(id,number,finishDate,startDate,status,triggered,statistics(property))