As others have said Accor Le Club can't cope with two stays on the same day. Besides the IT issue the T & C reason Accor seem to rely on is the member must be staying in the property to earn points and that isn't possible with two stays on the same date.

The only time I have successfully received points for 2 bookings on the same date was a day room booked at an airport followed by a overnight stay in a different city in a different time zone. The stays were consecutive rather than overlapping (I checked out of the first hotel 5 hours before checkin into the second but same day) but it still took Accor CS about two months, multiple emails, documentary evidence the stays were consecutive and a manual override with CS moving one stay to a false date to avoid a date clash before the points could be credited.

The moving of one stay to a false date seemed the only way to force the points credit.

The original stay auto posted and the second multi day stay failed to post in its entirety before the manual override described resolved this.