Benzelsanswered grow question 3 years ago It happens, more so outdoors but I had same thing happen to my Caramelo this year (check my diary to see how its going) Sometime bugs eat the new shoots and top or FIM the plants for you. Mine was FIMed by some bugs and ended up with 3 main tops after. Dont worry it will be fine.
the other option I think is a polyploid but I doubt thats what you have- if you do have it then congrats your plant will be a beast. Either way its nothing to worry about.