I have stainless steel pans that have been washed in a dishwasher for decades with no issue. However, I do know that if your dishwasher does not do a complete job of drying them it can cause rust spots relatively quickly. So if it isn't operating as well as initially, that could be part of the issue.
Also, it's a good idea to make sure you use a rinse agent, and If you have hard water use a softener (like Lemi Shine booster) or detergent that has softener built in. Hard water can be quite corrosive.