Hello, Many people on server noted there is low drop of soul, some people are offering 20b for 10s and such, is it possible there is something wrong with the drop ?
If you don't see any notes inside the official changelog thread it means there were no changes concercing soul drop rate, it's the same as it always was. Could you tell me who are the people you are refering at, because I always read the chat and I haven't seen anyone mentioning anything about soul drop rate or maybe you just think of this because some players are ready to pay a higher price if they need souls and got lots of bless to spare. Blesses are easier to be obtained and more important for the majority but when players start to upgrade their items in cm they need more souls so that's why you see them offering the 2b/1s rate which is a perfect normal trade rate. I suggest you hunt for jewel of soul in lower level maps (eg: devias/losttowers/icarus) over the higher level ones as the drop is better there.
Basic jewels like chaos, bless, soul are best to be hunted in low level maps as @Ezekiel mentioned because they require a lower monster level to drop from.