Sorry for posting in this old thread but this reply caught my attention:
In some sites every time you want to change client seed you will get new server seed.
If the casino automatically changes the server seed
after you cange the client seed then you should not trust them. If they know the client seed beforehand than they can choose a server seed which will produce results in their favor.
To answer op's question, most provably fair system use another variable beside the client seed and server seed to produce the random number, which is the nounce. Therefore, it doesn't matter whether you change your seed or not as it won't increase your chances of winning.
It's just another gambler's fallacy.
Well said, it is just a representation to show gamblers that their system is fair functioning and doesn't do any form of manipulation or changes to win. Every trusted gambling sites were provably fair, and the seed used to change automatically. If there happens any error this might not change, and by that time we need to change manually. Thi issue is common and today there is a thread for the same issue caused in Bitsler.