@Gheppo 

There is no option t change the channel settings on the RE450, instead, it uses the same channel as the main router and cannot be customized. 

Meanwhile, as far as I know, the RE450 won't affect the performance of the main router, you can try to change some wireless settings on the main router itself to give it a go. 

Or you can unplug the RE450 to do a comparison test. 

@Kevin_Z 

Thanks for the info, I have already tried reseting the some of the wireless settings and set each of the 2.4Ghz & 5Ghz channels to different router signals in my area that my devices pick up to stop any interference.

Also found that my printer was affecting the signal from my router as it was set to wi-fi direct by default and I switched it of and also unplugged the RE450 and my connection as improved 100%!

May try and reconnect the RE450 to see if it makes any difference in the future but for now I will just leave it as is. 

@Gheppo 

Thanks for your valued reply, and glad to hear that your connection has been improved. 

You can leave it as it is for now and check the performance, any further problems, just let us know.