Lindner met with senior FDP leaders in Potsdam to plan breaking away from the Scholz government 2 months before it happened on November 5. Lindner was fired that day by Scholz after making unacceptable demands including scrapping climate action targets, and reducing investments in infrastructure. The supplementary budget passed by Scholz was to reidirect 60 billion euros of unspend Covid money to needed infrastructure and climate action projects. The German Constitutional Court declared it unconstitutional.
The FDP is polling 4% which means it is headed to the situation a decade back where it had no seats in parliament. Which explains Lindner's actions seen as a betrayal by the Scholz government. The greens had advocated investment 4 years back which never happened because of Lindner and FDP opposition hurting the German economy's resilience.