The black spots are a concern - but then so is the almost white frost you're getting first... I don't know exactly what's going on here but I would worry about some type of fungus that isn't good at all! You've got to get your humidity down as well as your temps and get your fans working quick time! ... and then I'd use an organic fungicide on the entire grow to prevent the spread... something like Dr Zymes Eliminator (my favorite) which will ALSO kill off insects such as spider mites, thrips, aphids, whiteflies in all stages of their life (but I don't see any indication here that you have an insect problem) - just mix as directed and spray just before lights out. If you can't get that wherever you live (you'd probably have to order it from Amazon - https://smile.amazon.com/Amazing-Doctor-Zymes-DZE1QT-Concentrate/dp/B07C8C2GLY/ - you can try other organic fungicides but they probably won't be as effective... Neem oil, for example, is (imho) pretty useless...
But get the temps and the humidity (ESPECIALLY the humidity) down - temps in the 70s, humidity in the 40s to 50s....
Good luck!