strange leaves on red poison

Looks a bit like a phosphorus deficiency, also little bit stressed looking.

I agree with AsNoriu: Root rot/ph off and severe Ca + Mg deficiency due to lock out

root or ph issue. problems started long time ago, like 3-4 weeks ago. i think pot was too wet for long time, aka no wet/dry cycle, so that could cause root rot or so. you gave only biobloom and some epsom salt, thats not enough for girl. a lot things could lead to such state, but watering habbit issues are the first to blame in my mind. she will still produce some buds, but be more carefull with other plants.