Currently you can only add certain fields to reports with ID against them instead of Name, which results in a string of text.
Whilst you can fix this in text mode in most situations, this doesn't always work for groupings based on the ID field where you want Name instead.
Any manual fix also breaks the accompanied chart:
https://support.workfront.com/hc/en-us/articles/217982367-How-to-change-ID-to-Name-value-in-Reports-...