This lily appears to be growing solely on the bulb reserves rather than utilizing stem roots---probably because it hasn't yet developed stem roots because it didn't need them for moisture--it has too much already. Later on, once the foliage of that bleeding heart dies back and things dry out, it'll develop stem roots and should grow normally the rest of the season. Try moving this plant to a location that is drier during the first half of the season. It's been my experience that Regales and Regale Album like it drier than most lilies.
There may be other causes, too, like a partially rotted basil plate or just plain 'old age'---something internal that's unique to this plant that's preventing it from completing the benson/nelson cycle efficiently.
