@Terimor 

Hey

If you check the post below and look under Point number 2...   sadly you will find this is a very common issue.

https://community.tp-link.com/en/business/forum/topic/578366

In short the 2.4ghz frequency is heavily congested for most people, unless you live alone in the countryside its likely to be an issue for you also.   In terms of what to do?  The two posts list a number of things to try, however none are guaranteed..    Ideally, best avoid 2.4ghz if you can, its a very congested frequency.