The only other time I could find any IG refusing a request from a group of bipartisan senators was in the first trump administration, back in 2019 [0] when they were withholding congressionally directed funds for Ukraine.

[0] https://www.durbin.senate.gov/newsroom/press-releases/durbin-colleagues-statement-on-dod-oig-decision-to-not-investigate-ukraine-security-assistance-initiative-funding-delay

https://www.computerweekly.com/news/366559333/Encrypted-mail-service-Tuta-says-it-was-wrongly-accused-of-being-a-front-for-intelligence-services

It was good while it lasted. Join Digg and geocities I guess. Reddit In Peace