I created my first corridor with a strata for topsoil stripping(used strata surface option) and then generated the corridor earthwork report which shows the topsoil stripping, that all worked fine. Now in the same file, there is a Phase 2 where the finish grade is now merged with the original ground requiring another topsoil stripping strata on the new merged surface, even if you create a new site improvement name and surface name your previous corridor loses it strata quantification in the report. Can you only have one surface strata per TBC file or am I missing something?
Also, one lesson learned in this process when creating site improvements referencing a merged surface if your topsoil stripping(site improvement) doesn't fill/shade your whole boundary its because you had surface edges/breaklines in your original surfaces that don't show as members of your new merged surface. Display only the breaklines in your surface view options and pick additional site improvements in the missed areas.