I recently got a new WiFi router to replace the old and slow one. It is getting a lot lower of a speed that the company said. Is this because i have a cordless phone right beside it, or could their be other possible reasons why this is happening?
As @TJ Hooker said, we need a lot more info. Your performance may be completely normal. The advertising numbers that are used for WIFI "performance" are completely fictitious. So not getting performance like the box says "AC1900" thinking you will get gigabit performance is not abnormal.