I did not try this. The reason I am asking this in this community is that I was trying it out in Sync and could not get it to work. But apparently, using the block function on the post worked. Did I just find a bug?

I eventually tried this and it seemed to work. I might be seeing a bug here because by using the filter function, it did not work (I made sure the username I block is the same) but using the block function on the individual post worked.