Well....it does not mean automatically a new election. The CDU-CSU could linger as a minority government. The Chancellor in this position....probably would ask for a vote of confidence (from the 630 seats) and hope that he got 315 minimum. If that fails....the President would schedule a new election within 60 days....giving everyone a limited time to meet...get agendas lined up, and vote for a lead candidate.
If new elections are called for? This would likely occur by early December.
Polling? AfD leads most polls....around 28-percent. The CDU-CSU folks are polling around 19-to-21 percent. SPD? Around 13-percent.
Greens? 14-to-16 percent. BSW, at 4-to-5 percent (they'd have to pull 5-plus.....to get seats). Linke Party, at 10-to-12 percent. FDP currently at 4-percent...meaning they probably would not get seats.
If you asked me over the CDU-CSU candidate? Hendrik Wüst (CDU), Markus Söder (CSU), Thorsten Frei (CDU), Johann Wadephul (CDU), and Alexander Dobrindt (CSU) are the top five.
Public problem to drag upon such a election? Mostly economic woes, unemployment, public safety, and natural gas pricing.
The unusual conditions presently? Merz was supposed to be this super-fix for the economy, and nothing much has come of that 'brand'. Looking over the SPD and CDU-CSU 'promises'.....none of the two really can openly promise much over the economy.
Outcome? AfD would 'win' but be unable to form a coalition....meaning the weakened CDU forms with the Greens, SPD....to get a short-term coalition (probably no more than two years)....then another election.