Welcome NT!
Unfortunately it seems as if the school has misguided views on giftedness. You can be gifted while struggling with one aspect and not be able to demonstrate it academically.
I'd personally push a little bit harder but don't push too much, perhaps lean on supplementary Ed Psych report or transfer him elsewhere.
Any other concerns? While enrichment may be sufficient to maintain a child's intellectual curiosity, it may not work as well for 2e. Also... perhaps be transparent and remember that for gifted children they do not need to "fail" in one area to be learning disabled or dyspraxic. If all other areas are highly superior but one is average, that suggests a very clear weakness.
Perhaps typing or a laptop might suit him better as an accommodation in some areas.
