Rhljazz
You refer to to a high output setting which is the exact opposite of what you want with a high output MC. I looked up the spec for your phono stage and it provides a whopping 85 db on high and even a seriously high 60 db on the low setting. Most phono stages provide 40 db low and 60 db high.
I think you are overloading the input on the preamp. Try the lowest gain setting.
WTF becomes TWF (That was fabulous) . I do like a happy ending!