I am currently rereading cultivation chat group from the beginning, but when I got to ch383 I found it locked, which is strange as I have read and unlocked up to ch500 previously. I went to the contents list, and chapters 383 to 403 appear to be locked again, then the chapters continue to be unlocked until chapter 500 which was where I left off reading.
Is this a bug? Or do I really need to pay again to reread these chapters?