Marijuana flower closing up?

Ok so I checked my plants today,
and one of my plants 2 leaves have sorta fused together...
this is still early days in growing around 2-3 weeks
are there any particular species or reasons that should do this?

my other plant shows 2 leaves like it did this morning.

however the other plant leaves sorta just connected to each other...

I'm growing inside have decent soil water reguarly however my spray bottles was originally, a disinfectant bottle and then washed out many times.

Could that possibly be the reaons the plants are like this?
are they dying?

I Just want to know incase so i can save my others

i have had this happen to me and it is a good thing its about to take off in growing like crazy!!! when the leaves seperate ull have a good growth burst!!!