Slower broadband with switch to fibre
My Sky BB router is connected to an annexe where it's signal does not reach, via Ethernet cable connected to a TP Link n300 wireless access point, via two TP-Link TL-PA4010PKIT Passthrough Powerline Adapter plugs (to avoid looping over a fireplace).
I've just upgraded to fibre. Wireless speed from the router is 140 Mb/s; however, in the annexe it's only 70 Mb/s via the TP-Link units.
Before the upgrade, I got 66 Mb/s at the router and the same, more or less, in the annexe.
Any idea why I'm losing so much speed please when nothing has changed physically downstream of the router? I've tried turning everything off and on.