The hotter the pepper, the slower it grows, it seems. The Trinidad Scorpion was for a time rated as the world's hottest (I think it has since been superseded in the chili pepper arms race), so it is slow. From seed sprouting to first pepper would usually be 3-4 months.
That said, yours still seems like it is not thriving. Here's a picture I found on line of someone's TS pepper plant at 2 months:
Tell us more about the conditions your plant is growing in. You started it from seed? It is in a pot, in the ground? How much sun does it get? These peppers like lots and lots of sun and heat. Your UK climate may not be the best for it. Someone from UK wrote in here saying their temps got to 26 C (79 F), like that was a lot. That would be OK, if sunny, but it is near the minimum of what the plant likes to thrive in.