Certified GKH Gardening Expert
I believe it may be having nutrient issues. While I am not 100% sure on cyclamen, I know on other plants a phosphorous deficiency will cause a reddish-purple cast to the leaves and will cause flowering to fail. Add some bone meal to the soil to increase phosphorous and this should help.
It may also be an issue with temperature (which can interfere with phosphorous uptake) so if you can move it somewhere a bit warmer, that may help as well.