There is a quick fix to this issue but you must spawn in the dragon blood in manually each time you have killed a dragon. First you must find the Item ID of the dragon blood in your game.

You can find the Item ID by going to the console by pressing Tilda (~) to the left of the [1] key and typing:

help "dragon blood"

After entering in the command you should see a message pop up in the console box with some numbers. It should appear as:

ALCH: (>insert numbers here<) 'Dragon Blood'

The numbers in the paranthesis will be the ID of the dragon blood.

Now in the console type:

player.additem (>Insert 'Dragon Blood' Item ID here<) 1

WHERE IT SAYS (>Insert 'Dragon Blood' Item ID here<) MAKE SURE YOU ENTER THE NUMBERS THAT WERE SHOWN FROM TYPING help "dragon blood" AND DO NOT INCLUDE ANY ">", "<", "(", or ")", ONLY THE NUMBERS.

The "1" is the number of Dragon Blood potions you will get and you can always change the number to fit to your situation.

If you have any questions or if you have found a way to fix the issue permanently please share in the reply section of this post. I hope this helps, good luck on your adventures dragonborn!