Try changing the WiFi card to 2.4 GHz and disable 5.Same issue exactly this morning. Then I restarted the router and disabled and reenabled the wifi from my computer (NB for the umpteenth time) and now I'm getting 66.8 Mbps download / 18.3 Mbps upload. So definitely nothing to do with the computer position, internal walls, etc. I'm still mystified though, and concerned that it'll go back to tortoise speeds again. Any ideas?