My home setup contains a PC and NAS hooked up to an ethernet switch together with a WiFi access point in client mode that connects to my all-in-one WiFi router and cable modem.
Most of the time, when I access the NAS from my PC, the traffic flows from the PC through the switch to the NAS and I get the full Gbit/s bandwidth. When the PC is running for several hours, it sometimes happens that the traffic goes from the PC through the switch, through the WiFi access point then over WiFi to the router and from there back to the WiFi access point, through the switch to the NAS. When this happens, bandwidth is limited by the quality of the WiFi connection. For the love of God, I was unable to find why that is happening. Usually rebooting the PC fixes this issue for the next couple of hours.
The router acts as DHCP server and all devices have an IP address assigned by it automatically in the range 192.168.178.x.
Is there a way to force a path between two devices using an unmanaged switch?