My take, as someone who just read through the github issues conversation. The model was outputting reasoning traces that were supposed to lead to tool calls. S

My take, as someone who just read through the github issues conversation. The model was outputting reasoning traces that were supposed to lead to tool calls. So the model might do something like: <think> I should use a tool </think> ... should make the tool call here But a \n was slipping through from the last line of the reasoning trace so the parser was generating: <think> I should use a tool </think> And that extra new line before the closing </think> would occasionally trigger the model to question itself with an "Actually ... " digression. In long running conversations this would end up looping because the "Actually ..." part would reason it should call a tool, then a new trailing \n would trigger an "Actually ..." and then it ends up in a loop.