Could be the drawbar needs work, or worse, the tool is fretting in to the spindle. Oil is usually not recommended to put on holders except for storage. The oil can actually make it worse by hydro locking in to the taper. Could be your unclamp unit is not up to snuff, not pushing the tool out hard enough. Run the spindle up and see if you are getting any heat inside the taper as well. That can sweat tools in, but bad news as it could be bearings. Many many threads about haas here with the same symptoms.