I have a TP-Link PowerLink adapter plugged into mains electricity and connected via ethernet cable to my PC. Upon plugging it in, it works well, giving similar speeds to my WiFi and greater reliability. However, after a few hours of usage the speeds suddenly drop and do not return. It drops from 20mbps down, 8mbps up to 2mbps down and 5mbps up. Sometimes these slow speeds are preceded by a minute or so of near zero connectivity. The issue is not with the broadband more generally, as switching back to WiFi returns speeds to normal.

Restarting the PC does not help. However, if the PC is shut down, left for a few minutes and then turned back on, the issue is at least somewhat temporarily alleviated. When the PC is turned off overnight speeds through the PowerLink return to normal until running for a few hours again. I have confirmed the issue is not with the PC as disconnecting the ethernet cable and plugging it into another device while the problem is ongoing yields the same results.

The same results have occurred while the PowerLink is plugged into two different sockets, although both via extension leads. When the issue is occurring, the two lower green lights on the PowerLink seem to flicker faster than usual. The top green light remains constantly on. It feels like the adapter could be throttling speeds for some reason, as if it may be overheating or something like that? However, an identical issue has occurred with two different TP-Link PowerLinks so I do not believe it is a faulty adapter.