I am not a guru BUT yes I believe a GAI should definitely be calculated. Also, my son had similar low scores in symbol search, coding and block design (but his comprehension score was always high) when he first took the WISC . He had a vision issue and he has dysgraphia. About a year later and after a year of vision therapy (ad he started doing puzzles!) his block design went up to high average but symbol search and coding still abysmal. He has dysgraphia and Ehlers Danlos. Kids with dysgraphia and fine motor skill problems do very poorly on those tests. My son would never have qualified for any gifted rpgram without a GAI calculated.
