Not all seeds will grow perfectly, nature is not perfect, so to get a strange seedling once in a while is quite normal.
Strange seedlings will sometimes recover, but I have no time for "maybes" so I replace any strange seedlings without any guilty feelings.
Planting a few extra seeds more than you want/need is always wise, for occasions just like this, otherwise you get a choice of only the healthiest and best seedlings to grow if there are no strange seedlings that need replacing.
I would also suggest giving your seedlings an 18/6 light/dark schedule, plants need sleep and a dark period every 24 hours to have a completely healthy metabolism.
Nothing on Planet Earth can survive with their health intact when subjected to an endless cycle of no sleep, cannabis included.
18/6 has been proven as the healthiest and most effective light/dark cycle (circadian rhythm) for cannabis and this light/dark schedule is the result of more than 80 years of research into cannabis.
Besides, cannabis can only grow so much during any 24 hour period and this growth maximises at around 18 hours, meaning running your lights any longer than 18 hours is basically a waste of electricity. Do your plants a favour and give them sleep, they will be far healthier and a healthy plant will grow healthy flowers.
An exhausted plant from no sleep, and with a dysfunctional metabolism, will give you unhealthy and exhausted flowers.
I know which flowers I would prefer.
Hope this helps, Organoman.