Can't submit an Expense Report when Item Date equals a HR Assignment Effective_End_Date for user

Summary: Multiple errors shown when user trying to submit an expense report with multiple items all using same Type, Project and Task but different dates.

Content (required): One of our users has tried to submit an expense report with a number of items booked to the same expense type and project / task. The item with the errors (screenshot of errors attached) is unique from the other items in having an Item Date of 28.11.2021. Looking at the user's rows on PER_ALL_ASSIGNMENTS_M shows recent updates with a penultimate row having an EFFECTIVE_END_DATE of 28.11.2021 00:00. Seemed suspicious, then looking at the following date-tracked row for this user, it has an EFFECTIVE_START_DATE of 29.11.2021 00:00 (thus suggesting a time gap of 23:59 hours between those two