Why Did my Autoflower Take Long To Flower?

Is about stressing in flower and defoliation too autos don’t take how long they say on the pack once you start training them you can start adding days onto your cycle and if you just let them grow naturally in an optimal environment you might just get seed to weed in 8weeks but it won’t be anything special

You are on day 45 which is still in the normal range. I would not get concerned until about day 60. If there is no sign of flowering you can think about switching your light to 12/12 and grow it as a photo. I have used pots from 12L to 40L and there was no difference in the time to flower. The plants in larger pots grew larger and had more yield but there was no difference in "time".

Training, growing issues, strain, light, etc. can all play a role in longer flowering. Bigger it gets more buds you will have. Be patient. Everyone likes to say change light times etc. If it is a auto it will run its course naturally. Good luck