Separation/cracking behind paint

Sometimes it happens naturally as the two pieces of drywall move relative to one another. For example due to humidity changes etc. This causes the corner paper/metal bead to pull up and you see similar cracks. This happens more often in new homes as they settle.
Usually you address them by scraping, applying drywall compound, sanding to make it smooth and then finally paint.

However, in your case it could be a part of bigger problem that you are facing with your home.

This is your walls compressing down and the drywall tape popping out as a result. A result of your new beam.

Jerico wrote: ↑This is your walls compressing down and the drywall tape popping out as a result. A result of your new beam.

Just looked at OPs other thread about all the things on his house shifting, from drywall cracking to doors not closing. This is going to cost much more to fix than getting a permit in the first place. Good luck OP