@DanielGB Thanks for your reply. Cause other devices work properly and different linux flavors have the same issue, I'm afraid that it has something to do with the laptop itself. Have you ever tried...

@Gregor_F Below is the instruction to setup slave Deco as the main Deco. https://www.tp-link.com/support/faq/2400/ The Deco supports PPPoE connection, you can give it a go first. May it help.

@Lymfo Thanks for your reply. You can take your time to test whether it works well with the IGMP snooping/proxy box. Any updates, please let us know.

@wealthychef Thanks for your reply. You can give it a shot first, any updates, just let us know.

@soloking Definitely sure. Take your time to test it. Below is the download link of the firmware where you can compare whether the current firmware is up to date....

@Jorj Gotcha, you can configure them as the access point and connect them to the gigabit switch directly to boost network. If need more help, please be free to let us know. Good day.