What's wild there is that the suspension is based on tests from 2022 or maybe earlier (release from team says "This decision is based on checks carried out before his arrival in the team on January 1, 2023.").
He had a breakout year in 2021 so maybe it kicked off then
https://www.cyclingnews.com/news/decathlon-ag2rs-franck-bonnamour-suspended-for-biological-passport-abnormalities/