TP-Link live chat on their support page seems to have sorted it...Advance Tab > Wireless Settings > switch off auto channel selection in both 2.4 and 5GHz bands, choose individual channel and...

Note: "Model" field above does not have current models to choose from...hope this forum is still operating. Establishing connection to a new Archer VR2800 DSL Modem/Router with 18mth old Microsoft...