I (still) have the save issues with my PETG. I also use Overture. Out of the box, it prints butter smooth, but after a few days, it'll string, blob, and not stick. I live in SE-WI where the humidity can get in the 80% range and outside heat in the 90's+. My house stays ~70-72 (21-22C), and can reach on rainy days to 60% humidity. I use a food dehydrator to dry my filament before i print, and it'll last maybe 2-3 days before having to do it again. Desiccant packets are useless IMO. once they absorb their cap in moisture, they wont work anymore. I use the calcium chloride drying pods from the dollar store. They dry better, and keep drying until the pellets are gone. I had a similar issue with my PETG not sticking when it gets wet. I also found that, on my ender 5+, the pure glass backside of the bed works awesome for Overture PETG, but you have to let it cool before taking the part off, otherwise the glass comes with it... I do have a feeling my dehydrator may not be as hot as i need it though.