Luigi-s Mansion 3 -0100dca0064a6800--v327680--us...

That looks like a device or file identifier string. Possible interpretations:

Region (US): This confirms the file is intended for the North American market, ensuring compatibility with US-based save data and DLC. Major Features in Version v327680 (Update 1.4.0) Luigi-s Mansion 3 -0100DCA0064A6800--v327680--US...

Luigi's mansion 3 - sometimes fun, often frustrating : r/patientgamers That looks like a device or file identifier string

Here is a breakdown of the feature request based on the filename provided: Region: US Released on April 30, 2020, version 1

Part 5: Frequently Asked Questions

Q1: Is v327680 a hack or virus?

No. It is almost certainly a metadata error or a manually modified version string. It will not harm your Switch or steal data, but it may prevent online play.

It wasn’t in the patch notes.
Nintendo never mentioned it. The official changelog said only: “Various fixes to improve game stability.” But for those who knew where to look—deep in the hex of Luigi’s Mansion 3, version 327680 (1.4.0 for the rest of the world)—something else was breathing.