If you single step thru the attached animation, you’ll see the DISAPPEARER.002 object blink in and out of existence. That’s the major problem here (…today). EG, it’s there on frame 55 and gone on frame 56.
Why would that be? It’s function is to make PILLAR.002 disappear via Boolean action.
Attempt_201117a2COPY.blend (1.4 MB)
put the overlap threshold of the boolean modifier at 0
Didn’t work. Although it did change the nature of the failure-- the PILLAR object disappeared totally. I’ll read up on the function of OVERLAP.
Check out this video-
That was very informative. 
(Still struggling: see my “intersecting” question in Modeling.)
Btw you can try using 2.91. It has the new “exact” boolean
Submitted as a bug: resolved in 2.91.