It really does look kinda typically african sativa so far (I've grown a lot of them, as in hundreds), similar plants can be found in like, south and central america,
Anyway, about the slow growth, judging by the stem and growth stage some extra carbon, silica, calcium, phosphorus for rooting is often a bit overlooked.
If roots don't grow properly, they struggle (coz they tend to be rather large plants, 4m+ in good conditions).
And because they're used to good conditions, they're also like...sensitive often.
Cheers, best of luck. And yes, those sort of plants tend to grow for a long time.