I placed a line with 3 anchors, removed the middle anchor.
Then AI created automatically an infinite long handle from one of the remaining anchor points.
I coudln´t save the file, it crashed immediately and the recover file got the same bug, so I couldn´t even save the recovery file. the whole infected file is lost completely. (I lost 6 hours of work because of this bug).

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A HANDLE of a remaining anchor point automatically calculated to be infinite.
I did something like what is in that gif, perhaps something different but the same logic.
I did that and AI created an automatic infinite long anchor point handle