Is this drywall cracking a structural problem?
I'm not a structural engineer but I do have a fair amount of experience in dealing with drywall cracks of this type. First of all, there really isn't any way to be 100% sure of the cause of cracks such as this one short of bringing in a structural engineer. Having said that, be assured that in 99% of instances with minor drywall cracks the cause is not structural but cosmetic.
Over time houses and condos move and flex internally with expansion and contraction due to fluctuations in temperature and externally with shifts in soil around the foundation caused by expansive soil or changing water tables. The good news is that homes are engineered to withstand these stresses structurally although we will see the ocassional cracking in drywall or a door that starts to stick.
With structural damage you will usually see significant foundational cracking and major shifts in structural integrity around windows and doors.
Based on the description and the pictures provided it looks cosmetic - have the HOA repair it. However, for your peace of mind you might want to ask the HOA and neighbors  about other similar incidences in your community. If there are structural issues it would probably fall to the HOA to deal with them.