Germination

The temps probably were not the problem. i moist pot is a few degrees cooler than ambient due to evaporations occuring - barring special circumstances like a black pot being blased by the sun etc.. if it was an ungerminated seed, it was a bad seed -- assuming it was moist the whole time too. if it did germinate but never sprouted, that was probably user error. Use a small pot - ignore the dopes that tell you not to transplant an autoflower, that's nonsense. fill it up with substrate. Get it wet. Never partially water a pot. Press about 1/2" or a bit less into the top of soil -- while doing this you slightly compress a little falt spot that will securely hold your seed - it wont sink further. Pop seed in. Gently cover and gently tamp down on top. simple as that. You can use a humidity dome early on to avoid needing to water again before germination. Remove the humidity dome when it does sprout, unless you live in a very arid climate and normally use one early on. If sprouts come out wiht a shell too often, either temp down a bit more firmly or press down a bit deeper when you plant the seed. You want to be on the edge of having a shell-problem, because that makes for the fastest sprout time -- just enough to rip the shell off before it sprouts. pulling a shell off is no big deal. Hold 1/2 of slightly open seed shell steady with tweezers. This also holds the entire plant steady with no stress on stem or roots. Use a toothpick or similar to press on other side of 1/2 open shell to pry it open. If a membrane remains over the cotyledons, use the toothpick to gently slide if off the ends of the cotyledons, don't try to rip it off. Plant it and forget it. No need to manhandle a taproot - especially with an autoflower. Up-potting does not cause shock, but fucking with a tap root sure will. By the time you have to irrigate after sprout, it'll have multiple roots all the way to bottom of tiny pot. Water as normal. Water entire substrate, allow to dry/drink, repeat. Make sure to allow for a proper wet-dry cycle. never partially water. this will only cause the top layers to remain moist longer thna the interior of the substrate. this will cause roots to turn toward the moisture. that is bad. you do not want roots turning upward. you want them driving down. It is physically how they grow. roots turn toward greater moisture. watering habits are slightly different for soil and soilless but this remains true for both contexts. never partially water. Always water the entire pot. you don't pick the amount of water, what constitutes the substrate dictates that.

12 days is too long period w/o water. 2-5 days between adding water/misting around depending on how quick the top soil dries. I usually add a few ml every two days because it dries up quickly especially when it's +30c

Time to sow some more beans.

As he said but when you are in the soil only mist to start. You likely suffocated it

Could be different reasons. Bad storage, dead from the beginning. I prefer to germinate the seeds with a wet papertowel wrapped in Cling film. Within the last 3 years a had a success rate of 100 % (fast buds and dutch passion seeds). After I see the seed pop up and the root tip come out, I put it in the soil or coco in my case. Works every time.