Possibly for the purpose of adding to the ongoing list of hints to his supporters that Biden isn't in control in the first case, and to do the very opposite of that in the second case - as a distraction/psyop for the media & left. The wall building can begin again later, although that'll be extremely unlikely if they start actually tearing it down.

I do agree with the general suspicion here though. These actions can only go so far before it becomes completely implausible that Trump or Q or the Military are in charge. Just haven't quite gotten to that point yet.