ASM violation: Modified domain cookie(s)

i understand the risks of clients changing a cookie, but apparently it also is a regularly used way to achieve certain functionality right?

 

 

so is there some way for me to determine what is expected to be fine or not? or will this require having full understanding of what the cookie is used for?

 

 

and one final question, does this really only trigger when the cookie is changed by the client not when the cookie is first set by the server and then returned by the client?