Too dark and too warm I would guess Maren.
I don't grow many of these now as they are all terribly prone to etiolation under glass. Lobata is supposedly hardy so you could try planting some out.
The autumn flowering South Africans (yes I know lobata is not South african) I usually stand outside as the flowers develop to give them maximum light- they are usually finished before we get any frost, by which time they are back under glass and I don't care if they etiolate then.