Why are you not allowed to overtake now?

You answered correctly. The rule here is that you are not allowed to overtake when a cyclist could turn left at any time. Cyclists have the right to use the full lane when preparing to turn, and they may indicate late or not at all. This makes overtaking unsafe or unpredictable. German traffic regulations emphasize extra caution around vulnerable road users like cyclists, especially when they could change direction. So, if it is possible that the cyclist might make a left turn, you must not overtake. This helps prevent accidents and ensures everyone's safety. Remember: Always assess if the cyclist might turn or move across your path before attempting to overtake.