Having the same issue with a WD90T754DBX/S7.
First Samsung updated the Washing machine Android app a few months ago and made it horrible, we no longer have laundry recipes, which was a very useful feature. And also the new options for washing in the app are horrible, you can't even dry your colored clothes in one session, you have to dry them separately after washing.
If crippling the Android app features for no reason wasn't bad enough, for the last month or so I had issues with the washer showing as offline in the Android app.
My Wi-Fi works fine, it's a Wi-Fi mesh consisting of two routers, and the Washing Machine is less than 7 meters from them. The Wi-Fi symbol is showing on the washer display. In fact I can even ping the washing machine from my PC just fine, so it's clearly not a Wi-Fi issue:
Pinging 192.168.50.28 with 32 bytes of data:
Reply from 192.168.50.28: bytes=32 time=14ms TTL=255
Reply from 192.168.50.28: bytes=32 time=31ms TTL=255
Reply from 192.168.50.28: bytes=32 time=41ms TTL=255
Reply from 192.168.50.28: bytes=32 time=58ms TTL=255
My internet is Gigabit Fiber, and it also works fine:
However, the washing machine shows as offline most of the time. The diagnostic tool doesn't fix anything. Removing it and adding it again to the Samsung Cloud doesn't fix anything.
It's showing as online for a few seconds, then it shows as offline in the app again for minutes. Clearly this is a Samsung/Samsung cloud problem.
In the past when it behaved like this it was caused by weak Wi-Fi signal, but that's not the case now. I even moved the 2.4 MHz network to a less congested Wi-Fi channel, the issue persists.
Sometimes, after waiting for hours, it stays online long enough so I can start washing something. It took one hour of useless troubleshooting and another hour waiting last weekend before I could use the app to start washing.
This weekend, I'm playing the same cat and mouse game with it, trying to catch it online to start washing.
In the past I tried to report issues to Samsung, but Samsung Romania customer support just closed my tickets about Samsung Smart Things, repeatedly, without helping me, claiming Smart Things is not a Samsung Service.
I just sent feedback one more time about these issues from the app, I wonder if this time they will just close my ticket again without helping me.
The diagnostics, telling me to add it again to the Samsung Cloud, when that's not actually the problem:
As mentioned, I already did that a few times last weekend, and it didn't help. During the process it was even warning me that the machine is already in the Samsung Cloud, and I have to remove it if I want to add it again, so clearly the diagnostics are wrong about the problem.
Today, after one hour, after catching it online for a few seconds, I was finally able to send a wash program to the washer and started it from the start button of the washer.
I would have preferred to use smart control, and do everything from the app, including starting the cycle, but I've noticed that enabling smart control makes it more likely that it will show as offline in the app.
I activated Smart Control after starting the wash, and, while I was typing this, after initially showing the washing progress in the Android app, now it's showing it as offline again.
And this continues, it shows "Washing 6 hours 39 minutes left" for a few minutes, then offline for a few minutes, then "Washing..." again, and so on. Horrible experience.
Needless to say, with all these problems, it's very unlikely that my next washer will be a Samsung.
