I have had the same kind of delays with X50 Deco. Applications tell you there is no internet, but after retrying or waiting, there is!

  @MarcoVa

Hi, i recommend you to confirure a HARDWIRE [Ethernet Backhaul] in all your satillete nodes. 

• Set Main Deco as Router.

• Connect your main deco to a L2 swtich and then all your sattelites nodes and configure then using static IPv4 addresses.

└>If you dont have a switch cand do it by conecting main decho to LAN Port next DECO and so son.

•Check your network stability (which should improve a lot by doing this) 

https://www.tp-link.com/ar/support/faq/1794/

I hope helped you, 

Regards,

  @OxDragon91 thanks for your time and reply. Appreciated, but actually I would like to solve the issue wireless. I doubt the effort for wired connection (nicely done) is worth this issue of waiting 15-30 seconds... 

  @MarcoVa 

Hi Marco, i hope you are doing well, i recomended this method just as discard process, you can connect all decos together using small ethernet patch cords by tryng first method.

Then you can verify if your problem keep active.

•-In my personal experience as a IT Specialist | network tecnician i can say having network sattellites comunicating betwenn them using wireless signal its terrible a idea and it has a terrible performarce.

• Perform a full device reset and test the following:

• Try an ethernet backhaul / hardwire solution, and validate if the problem continue.

• Try testing node by node as a main router.

• Update firmware Nodes.

• Check and update your WLAN NIC driver to latest version.

• ***Try booting on a linux machine [ubuntu iso maybe]  and validate if same thing happen, if yes this could be something related to a driver layer****

I have installed many of this kind of kits and always i recomend to my client to hardwire them whire finally ends happy with resuelts, if nothing mentioned above solve your problem maybe some of your units could be defective and shouldbe replaced.

Best Regads,

Joseph.