I recommend to check the suggested book section in the flair user page of /u/Libertat at first.

From Anglophone scholarship, I'll also add to the following collection of essays to the suggested list, though nearly all of them are now classics:

• Drinkwater, John (ed.). Fifth-Century Gaul: A Crisis of Identity? 2nd ed. Cambridge: Cambridge UP, 2002 (1st ed. 1992).
• Mathisen, Ralph W. & Danuta R. Shanzer (eds.). Society and Culture in Late Antique Gaul: Revisiting the Sources (1st ed.). London: Routledge, 2001. https://doi.org/10.4324/9781315242828
• Noble, Thomas F. X. (ed.). From Roman Provinces to Medieval Kingdoms. London: Routledge, 2006.

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• Mathisen, Ralph. Roman Aristocrats in Barbarian Gaul: Strategies for Survival in an Age of Transition. U of Texas Pr., 2011 (pbk: hbk was published in 1993): is another classic monograph.
• Some newer studies like this collection of essays, Social Dynamics in the Northwest Frontiers of the Late Roman Empire: Beyond Transformation or Decline (2017) focus also on the latest archaeological research.