Clearly you have a humidity issue. The poo looks fine when you see liquid and solid pee it is just the snake is well hydrated, in the wild in Africa water conservation in the snake is critical, in captivity with a water bowl it isn't much of an issue so they often have extra and expel it as needed.

Humidity is a bit complex. RH is a variable measure it changes with temperature. The amount of water the snake needs to shed is a constant. You need more humidity, I am not a fan of paper towels, they actually draw humidity from the air (hydroscopic) and hold it away, there has been recorded cases of snakes eating paper towel and it causing death. To my knowledge it is the only substrate known to kill. I don't think there is a big upside so any risk is not worth the advantages IMO. Coco coir, and cyprus hold a lot of water and will add a great amount to your humidity. A larger water bowl will also help and if you can post a picture of the vent holes I might be able to offer a change of location that also can help humidity.

If you post you typical ambient air temps I can suggest a RH% that will work for your shed issues. The question you should be thinking of is what is the % Rh is of? The saturation point of the water is what the % is of, it varies with ambient temps as the air is cooler than 80ºF you need more than 60%. As the temp increases over 80ºF you don't actually need 60%.