I have laid out 2 horizontal pieces of Wall, one in continuation of the other;
-the 1st has multiple Components;
-to its right is the other Wall, much narrower and with only the default 1 Component.

1) The first problem is that the part of the shrinkwrap where one Wall ends and the other starts (a small vertical line) remains there; in all my previous work with Walls, the line between them would go away, producing a seamless wall. What happened in this case? Is this the way it should be?

2) The other problem is, I tried to get rid of that line with the "In-place Wall Cleanup" ribbon tools, but I don't what tool to use, so any help would be appreciated.