Can't place blocks adjacent to grass path

I'm near a village, and I'm trying to replace some of it with blue concrete, a new block. It's impossible to place a block adjacent to a grass path block (next to it, above it, and probably below it). I've tried only with new blocks, which are blue concrete, blue concrete powder, and blue glazed terracotta, and all of them had the same issue. I had a torch in my offhand that was working fine, but I couldn't tell if it was because a torch isn't a full block or because it's not new. My guess would be the latter. I haven't tried to see if I've had this issue with old blocks, but this problem goes with the new ones.