Can also confirm. I even reproduced the issue with the attached video below. In the attached video, I used a sword with faster attack speed for demonstration purposes, and you may notice that the sweep attack does not work even while the player camera is being moved, in addition to the player movement. Additionally, when stayed focused long enough (i.e. not moving the camera and position), a sweep attack can be done once.
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P.S. The 'Johnny' Vindicator demonstrated in the video footage is modified to have longer 'follow_range' attribute using '/attribute' command to better exemplify this behavior. After running away from the creaking far enough, it will retarget towards it, and the cycle repeats.