It can cause more damage than good tightening the box. One of the dangers of following youtube instructions. Does not tell the full story, well, I have not seen a video yet which does tell the full story. Often wondered if the video makers are steer box repairers drumming up business. If you google or search on here steering box adjustment, you shall find much discussion.
They are beautiful things if you pull them apart. The tightening screw is a shuttle cock design, so when loose the shuttle cock shape follows the contact of the full extension of center to full left and right. So you want tight enough in the center but not too tight that grinds the shuttle cock every time you are in center. It is easy to over tighten, which shall cause binding. Normally it should be 1/8 turn is plenty. Hopefully you have not driven it too much and caused damage. The center is where they ware out .
Best practice I have found is to lift the front. Loosen the screw, turn steer wheel full to left and right then back to center. Then tighten the screw just till you feel the shuttle cock make contact and grab. Check play in steer wheel, if more than 40mm then try 1/8 turn. If not enough, make a mark where the slot is aligned to, loosen again turn left right then center and tighten again, and so on. If you over tighten it, they ware out very quickly every time you drive straight. They are sensitive.
Hopefully you checked your tie rods first. Steer box is often best not to fiddle with. I find it hard to describe, but it is clear if you pull them apart. Do not over tighten them.