Fastbuds girl scout cookies, nit surebif it is nute burn or light stress

And sorry i meant phosphorous deficiency and/or potassium burn. Just like 8thchevron said, unless it is green on the underside. And if temperatures are bellow 20° it may also be a response to the cold. I even confused myself on what i said, so it could be a little too much of Potassium, too little Phosphorous and too much Nitrogen. If you got something like 1-5-2 or anything similar or even 0-3-1 or 0-52-32( as long as it is used in really small doses) then you can fix it by using just water on the next watering, it you see the stems getting even more red and its not cold nor a itense light tanning them, then u proceed to apply a PK fert high on phosphorous low on potassium. If the branches are just tanned from lights or its just due to a really cold weather then use something morr balanced like 0-2-2 or 0-2-3/0-3-2.

What do you think would be the best to do to correct my mistake

Looks like phosphorous and/or potassium burn. If the branches coming from the main stem keep coming red/purpleish then its potassium doing the burn, if the issue gets fixed and branches start coming out green then it could be either phosphorous burn or both phosphorous and potassium. When u use too much of these it can also inibith the uptake or calcium, magnesium, zinc and iron.

Thanks for the feedback, what do you think would be the best step forward , should i feed flower instead of bloom?

Its nitrogen toxicity during flower. If it keeps going the tips will curl. Once it stops spreading you know you're good, those tips will stay yellow