I am sorry to hear that. I have printed multiple versions - mainly to test the translucent factor - but I never had open ends. Can you send me a picture via DM and more information about your printer and filament?
hmm, you could try to set Quality/Speed to 0.3 or 0.2 and click the "Adaptive! button.
This helps to print cleaner round objects. Maybe change also the radius/Smooth setting.
I am sorry, that's strange; I printed it with the normal PLA basic red from bambulab, so explicitly, no special translucent filament. My goal is that it works with any default PLA.
As visible on the animated gif, the LED tea light is enough to let the heart glow. Maybe your LED tea light is too weak?