The frame
On the Met's timeline the First Intermediate Period, from Dynasty 8 to mid-Dynasty 11, is dated about 2150-2030 BCE. According to the source, by the end of the Old Kingdom centralized power had weakened, and in this period Egypt was ruled by two competing dynasties, one based at Heracleopolis in the north, the other at Thebes in the south; the overview says that power decentralized, "only to be unified again" by the Theban king Mentuhotep II in the Middle Kingdom. The site follows the Met's timeline here, as for all of Egypt's periods up to the Middle Kingdom. Source 1.
Boundaries and overlaps
Both boundaries run inside the sequence of dynasties: the period opens with Dynasty 8, Dynasty 7 not being mentioned on the page, and it ends in the middle of Dynasty 11, where the Middle Kingdom begins. The page of the Spanish mission to Heracleopolis places Dynasties 9 and 10 "around 2100 BC", within the period, but dates a tomb in the city's cemetery "around 2000", that is, after the start of the Middle Kingdom according to the Met. The cemetery itself is described there as one of the First Intermediate Period and the beginning of the Middle Kingdom. The site does not move the dates to fit the boundary. Sources 1, 2.
On this site
One article is placed in this period: "Heracleopolis: the northern capital of Dynasties 9 and 10", which presents the city's status and the source's two dates on either side of the boundary. Source 2.
What is missing
The period has a single item on the site. Checked: the Met's timeline, the page of the Spanish mission, and the Asyut Project page of the Free University of Berlin, proposed as a source for the governors' tombs at Asyut; that page could not be opened (the site blocks automated reading), and according to the earlier summary of it, it gives no tomb owners' names, dates or finds, so no article was written on it. Missing: a second item with a dated phase in this period, for example an excavation publication or catalogue entry for the Asyut tombs that names their owners and dates, or a museum object whose record dates it to the First Intermediate Period. Sources 1, 2, 3.