Those are not structural most likely. They surround an adjustable or concrete filled steel post. If there are a bunch of them the flooring should have had an underlayment put down (IF the manufacturer allows on) to basically pack the floor up the correct level. Was the floor flattened to within the manufactures tolerances (usually 1/8 over 10')? Looks like you are going over tile. What was used r how was the slab set up with waterproofing or a vapor barrier? If there is any moisture present (and there almost always is in concrete) you will have a mess in short order.

We used dri core in our basemtn for old school vinyl plank it might work with yours too . It sure needed to be dealt with before you started install I have actaully never seen something like that .

We did put underlayment. That’s the white checked surface that you see in the picture. It is not on a tile surface. Even with the underlayment, it does not seem to be even in this spot. We are done with the flooring half way. So now not sure how to handle this space.

There is only one such spot in the entire basement. This one pillar has these around and the planks are bulging out.

I would open up at least this one column to see what you have.

at the very least use a floor leveler to prep the surface before you go any further.

,,, remember? the finished product is only as good as the prep.

" There is only one such spot in the entire basement. This one pillar has these around and the planks are bulging out. "

Time is passed then to figure out leaving that and the flooring will definitely break off the interlocks if not flat. Remove the column cover and see what you have but whichever type post it is "should" be buried in the concrete and you will have a flat surface. Guaranteed that column is a cover, the tell is the galv "L" brackets holding it down.

Hmmm for a basement I would just box the bottom area where the l brackets stick up and call it a day maybe consider boxing the whole pillar to get away from the fluted column as it's dated

I would remove the current cover and then design a square cover. (Look for ideas on Pinterest.)

Include some type of base trim around the bottom, and maybe add add'l trim to "build up", so that it will extend out until your floor is back to level. (Hope this makes sense.)

It's also possible to "block out" a larger column before you cover it.

Brainstorm whether it should match the floor color or other features of the area.

I would plan to attach the bottom trims with Loctite (etc.) and NOT through the flooring.