Ive had wifi issues with my Galaxy s10+ since I took the phone out of the box and updated. "Internet may not be available" warnings were popping up every single time I connected to my network, and I never got any internet from the connection. I tried everything from forgetting the network, force rebooting, booting in safe mode, clearing cache partition, EVERYTHING. Today I FINALLY FOUND A FIX.
Open the default phone app, click the 3 little dots in the upper right hand corner, settings, click on wifi calling, and TURN IT OFF.
UPDATE: Spotty temporay fix, still getting the error message more often than not.
Have same problem, s10 plus, wifi calling off. I have had some small things, like the wifi just drops out, like says connected, but internet not available, and I had a friend that connected to a wifi router (with a Samsung J4) my S10 did not even find the network when scanning?
Same issue. Have tried everything, even resetting to factory. The wireless on the phone, while showing connected with strong signals, just cuts out for 30-60 seconds. I have tested my other wireless devices while this has occured including another Android phone. Can say for certain it is the s10e, and not my wireless AP, router, or internet connection. It seems like there's most likely a bug in the firmware happening in the WMM feature (IEEE 802.11e).
Any update for a fix on this issue? It is still happening with the March 2019 security patch.
One thing I've noticed about the s10e is that packets are getting dropped by the ethernet interface on my router. It is the only device on my network that packets are actually getting dropped by the physical interface. I can run all devices on my network fine for days, gigabytes of information passing through that ethernet interface on the router, but as soon as the s10e connects to my network the packet drops start occuring on that interface. They are RX drops, meaning the packets transmitted from the s10e are being dropped. Even when the router is under no load by other devices. An output from 'ethtool' shows no rx_queue drops and no rx_*_errors, however, the output of 'ifconfig' shows RX packets are being dropped whenever the s10e is connected.
The issue with the wireless cutting out, showing connected and stalling, or popping up the exclamation mark, seems to occur the most when high priority traffic (DSCP EF and CS5) is being transmitted through the network. Primarily when VoIP (real-time traffic) is in use. The s10e on my network is currently marked as best-effort priority on the network (DSCP CS0). Most traffic on my network falls in to the best-effort category. Since I run differntiated services with 4 tins, and per host fairness fairness for bandwidth it should not have any issues, as none of my other devices do. Basically, my network is designed and able to maintain low-latency to all devices, giving certain traffic a bit of priority, while ensuring bandwidth is shared evenly amungst the number of devices wanting to consume it. No device ever starves. The s10e is the only device on my network having issues.