Liz,
Can you remember when you had wrigglers from the angels and Discus were there any changes in you routine? Any feeding, temperature, change in
time you do water changes, different water conditioner brand. Somehow there is a change or maybe the water company added a higher disinfection.
We can only check our water with what is available to us but the water companies have more specifically testing tools.
Second question the high gH makes it more difficult to hatch but the eggs can still be fertilized.
Cliff