How to check provably fair results

Before you bet, note the hashed server seed and set a client seed you chose. Play. When the site rotates the server seed, it should reveal the old one.

Hash the revealed server seed yourself. It must match the hash you were shown. Then run the documented algorithm — or the site’s verify button — with client seed and nonce.

If the hash does not match, stop playing and screenshot everything. If it matches and you still lost, the round was fair and unprofitable. Those are different problems.