Sorry to say it is mold. Manage your humidity, airflow, and get rid of that exhale bag. It looks like it is a mold factory. Supplemental CO2 does no good for the vast majority of hobby growers. You need high light intensity and a tightly controlled, closed-loop environment for extra CO2 to add any benefit.
I would carefully cut off the affected flowers and throw them away. It is probably a good idea to spray the rest of the plant with a dilute mix of hydrogen peroxide as a preventative. Be sure to do a peroxide bud wash when you harvest the remaining flowers.
Just pour a 5:1 water/peroxide mix in a spray bottle and spray the plant just before lights out.
I suggest using distilled or RO water for the spray mix.
I would also spray the second plant. You are going to liberate a lot of mold spores when you cut the affected flowers off and you don’t want them collecting on your plant.
Temps are too high and you should try to get it down. Max temps should be ~31 or 32. Humidity is okay at 40%. I’d point the finger at that exhale bag. You shouldn’t be having trouble at 40%.