a lot of searches default to the telstra modem login

[almerta]

A lot of searches default to the telstra modem login. I am using safari and deleting the cookies does not help

[Mkrtich]

Hi - If you are using a Mac, did you clear the Safari Data Cache as well. This URL shows you where the Empty Cache  is located in the Develop Menu. 

https://www.macworld.co.uk/how-to/clear-safari-cache-3496193/  

[almerta]

Yes I did clear the cache and cookies and this had no effect. 
thanks for reply. 

[cf4]

You could try changing both the IPv4 and IPv6 DNS in the modem's advanced > local network settings. Select DNS from drop down list and save settings then disconnect and reconnect MAC. Image below is of Aradyan modem, the Technicolor modem is similar.