Humboldt Apple Blossom/Blueberry Muffin

RoomForBloom Glass method from "Pott Planter" with a little bit of water and a few ml of hydrogen peroxide (H₂O₂) Update!!! Both seedlings died after about 1 week due to mysterious circumstances. They both germinated very well with good and healthy roots but sadly after transplanting them into cardboard seedling pots they both never came out to see the "sunlight". Today I carefully removed the soil just to find both seedlings to be dead and already withered. I've never had something like this happen before but the error clearly must've been on my side after them germinating properly. However I started 2 new seeds but due to lack of antoher "Apple Blossom" we are now running a "Humboldt - Blueberry Muffin" and a "Zecret Flavourz - Rainbow Zoap" instead. If you have any tips and tricks for me to prevent future grows to end like this or similar things happened to you, please let me know.