Von mir wird nachgedacht – verständlich/korrekt?

– yes. (Grammatic) correct – also yes. But that’s not a native speaker. The first two alternatives you have specified sound much more natural. The first sentence is the preferred version – if the one or the one is actually about to make himself thoughts about the problem.

The second sentence (considering the problem) could be heard, for example, in a press conference if the spokesman of the organization, who is holding the PK, answered a corresponding question, had no idea (or should not say anything) and tried to avoid it. For example, something like:

“How do you plan to deal with any problem with ?” the reporter asked. “The problem is being considered, but so far we have not yet come to a solution,” the spokesman replied with a pressed sounding voice, who was told that she knew exactly how weak the answer she had to give.

“They have been thinking about this problem for x years (x replaced by any number)! Or at least pretend to do this… people are gradually tired of waiting! Tell your bosses to finally make a decision! Even a bad or false decision is still better than that uncertainty and dissent! Because decisions can be corrected. Otherwise, it can happen that someone else takes the issue of action in hand – and is that really what you want?”, another reporter enraged on the evasive answer and got loud, agreeing comments from the auditorium.

“Then they would have to take responsibility – and they fear how the devil the holy water!” the observer muttered quietly in front of the screen from which he observed the PK.