A couple of my users have pointed out this apparent bug to me, and I've also been able to reproduce it myself. This happens in both versions 2.2.3 and 2.3.4.

When attempting to edit the estimated number of hours to resolve a defect, Contour will seemingly accept decimal values (e.g., 2.5) without giving any sort of error, but after saving and reopening the defect, the estimate value did not actually get saved. If I instead use a regular integer value (e.g., 3), the estimate does get saved.

Having Contour accept "invalid" entries to a field without giving an error and then throwing the data away is potentially a big problem if the users don't notice that their changes were not actually accepted and saved.

Is this a known issue? Is there a fix available?