We have a TP-Link TL-MR3020 router that is connected to a switch containing 4 computers. We also have one computer connected to the router's WiFi. The TP-Link uses a Huawei 4G modem to connect to the internet.
Now, here comes the weird part. If the 4G modem loses internet access (no service due to bad connectivity), then the computer that is connected via WiFi loses the connection and cannot connect via WiFi until the 4G modem regains internet access. I've never seen this kind of problem before, and neither heard that this is how a router is supposed to work. There are no settings that point towards supporting this kind of behavior.
Has anyone seen this kind of problem before?
It is worth mentioning that the LAN connection is still working, so the 4 computers on the LAN can still access each other as expected.
We should be able to use WiFi even though there is no internet connection, right?
DNS is on, if that is something that might interfere here.