Why a spike but no flowers

[SouthPark]

Originally Posted by ArronOB

Thinking about it, this is only a young plant so 4 spikes is a pretty good effort. I’d like to get it flowering properly.

That could be a contributing factor too. If it only has so much energy to use, then it might have to limit the number of buds or flowers. Otherwise - genetic considerations - that's if the plant keeps doing the same thing every time, while none of the other ones you've ever grown exhibited that behaviour.