Hi @Mjconwayjr,
There were some conversations (for example, https://community.canvaslms.com/t5/Canvas-Question-Forum/Importing-Section-Due-Dates/td-p/644434) that have happened recently in the Community about the course import feature, sections, and assignment dates.
If I recall and if I understand your original post, when dates are assigned assignments to specific sections in "course A", when "course A" is imported into "course B" (which also has at least one section, whether the default section or another section intentionally made either by the GUI/SIS/CSV) those dates are not assigned to assignments because the import process does not know what to assign them too.
Am I understanding you?
-Doug