Thank you all for your input and suggestions.
I used a long ethernet cable, and it was working, thus establishing the problem was within the home.
Focus obviously turned to the tp-link AV500 adapters I use, and it appears a Firmware update sorted the problem.
I'd had the Powerline Adapters for quite a while, so that explains it. FWIW when scanning thru the frmware release notes, I noted comments about compatibility with a few smart phones being addressed with each update, so it would appear tp-link are quite proactive in addressing such problems! I didn't get involved inthe details.
Result! Thanks for you help guys.
I had the same problems using the TP-Link AV500 PLAs, after reading this thread I did the firmware update. IPC6023 error has stopped happening. Thanks for the solution.
Just to add one more thing...
I was helping a neighbour sort this problem (he bought them on my advice haha) and I should point out that you may require two different firmware upgrade procedures. I forgot this the second time round, and BTTV problems soon returned.
We had kits containing 2 x TL-WPA4220 (2 ethernet and wifi each) and 1 x TL-PA411 (single ethernet - for connecting to your router). The TL-PA411 used a different procedure (and software) to the TL-WPA4220.
Check the model numbers on your units, and make sure you apply the firmware appropriately. It can be fiddly to be fair.
Hope this helps somebody!