Did you open the incubator in the last 3 days at all?
Even though the hygrometer reads 70, if you open the incubator the humidity drops fast. The meter may not even read the drop it is so fast.
During the time it is open, and it only takes a minute or two the membrane will dry out. For some reason they do not seem to 're-moisturize" even with the high humidity.
I had to learn this the hard way. I could not understand why I couldn't look at them and close it quick.. The moisture in the membrane leaves VERY VERY fast..
That is why the last three days are called lock down...
I have tried everything on the heat shrink wrap. if they are developed enough you can pick it off.
If they start to bleed....EVEN ONE MINUTE DROP!!! stop and leave them alone for 12 hours or so. Yes, you will lose some. but you might save some too.
If you really want to save them....(NOTE this is my experience hatching other eggs. I have NEVER hatched a DUX!! Ever, ever, never.)