DS's paperwork stated he must carry a minimum of 12 hrs per semester to maintain scholarship.
BTW, AROTC stipend is paid thruout the summer months unless they get paid thru some other training or Army progm (LDAC, CULP). DS went to air assault an since it was only 2 weeks he did not get Army training pay but continued to receive his stipend all summer until he went to LDAC.
I believe the reason your son received the stipend over the summer as a rising sophomore is because he is in ECP. Since these cadets attend LDAC after their first year they receive the summer stipend (except when they are at training).
Cadets in standard AROTC programs do not receive the stipend over the summers following their freshman and sophomore years.