One UI 9 is breaking Wi-Fi, mobile data, and even SIM detection for some Galaxy users

Samsung has been rolling out the stable One UI 9 update to Galaxy phones over the last few months. Although it introduces several new features and brings some Galaxy AI features to older Samsung flagships, the update process doesn’t seem to be going smoothly for everyone.

According to threads on Reddit and the Samsung Community forums, several users have been experiencing connectivity problems since installing the One UI 9 update. The problems range from Wi-Fi and cellular data issues to phones failing to detect SIM cards.

Wi-Fi issues in One UI 9

Multiple users have said their phones connect to Wi-Fi networks for a while, then randomly disconnect with a “connection failed” error. Apparently, restarting the phone or toggling airplane mode temporarily fixes the problem. However, after another couple of hours, the Wi-Fi disconnects again.

One user said that their phone no longer connects to their home Wi-Fi network, but other saved networks work fine. Another user said their phone connects to 2.4GHz Wi-Fi networks but can’t connect to 5GHz networks, while their other devices connect to both Wi-Fi bands without issues. A Galaxy Z Fold 7 owner reported that their phone can connect to Wi-Fi, but Wi-Fi calling with T-Mobile hasn’t worked since the update.

According to one user, the problem can be fixed by going to Developer Options > Connectivity Labs and turning off Wi-Fi 7 Mode. However, it’s worth noting that other users have highlighted that the Wi-Fi 7 option isn’t showing up on their phones at all.

One UI 9 mobile data and SIM card issues

While Wi-Fi bugs appear to be the most common, some users have also reported mobile data issues. Users on the Samsung Community forums report that their phones aren’t connecting to mobile data and apps won’t load unless connected to a Wi-Fi network.

According to reports, resetting network settings, toggling airplane mode, and even removing and reinserting the SIM card don’t seem to help. Meanwhile, a Samsung Community moderator has recommended that users try booting into Safe Mode or performing a factory data reset to resolve the issues. However, one user responded that a factory reset still didn’t fix the mobile data problems.

Mobile data and Wi-Fi aren’t the only problems users are facing. A Reddit user said that their Galaxy A56 stopped detecting either of their two SIM cards after updating to One UI 9, adding that a diagnostics test shows no SIM card is inserted. Other users have reported similar problems on the Galaxy A36, Galaxy A52s, and the Galaxy S24 Plus.

It’s unclear why so many connectivity issues are popping up on phones right after a stable One UI 9 update. While hardware issues are a possibility, with so many devices affected immediately after an update, a software glitch is far more likely.

We have reached out to Samsung and will update this story when we hear back.