I just bought this machine less than a month ago, only have 15 cycles on it, and it has happened at least 2-3 times to me. So it is working sometimes but sometimes not. I have not used "sanitize" or "high-temp" option. I also run the self-test and at the end it pops open the door as well. There are multiple threads in the forum talking about similar issues. I opened this one to keep a record for myself. The next step is to try some grease on latch as suggested by some threads.
here is a very long thread with a lot of infor: https://us.community.samsung.com/t5/Kitchen-and-Family-Hub/Dishwasher-auto-release/td-p/1101335
I'm sorry to hear that, does this occur on all cycles? Also, do you see any error codes or flashing lights?
Tonight, it happened again on a "normal" cycle. So there have been two concecutive "Normal" cycles that end with this problem in the last two days. Tonight, I also immidiately tried a "60 express", and the door was also not opened at the end even though I could hear the fan noise (I assume the door should be opened at this moment so the fan can blow the heated air out and speed up the drying).
In any case, no error code. I also got the notification on my phone saying the job is done.
As I said, earlier today, I have tried an "auto test", it can open the door at the end. I dont know what is the trick here.
I found some information in the user manual that maybe of some help on page 35 - 36