Hello,

I’ve been experiencing major internet issues for about a year. Initially, I was using 2 Deco M5 units, which I replaced a few days ago (X50 POE), thinking the problem came from that hardware.

Here is the equipment I use at home:
MacBook Pro, iPad, iPhone
Desktop PC (Windows 11, connected via Ethernet)
Work laptop (Windows 11)
My Home:

95 m² single-floor apartment, built in 2020. Each room has Ethernet outlets wired back to the utility room, where the modem/router is located.

Network setup:
Modem/router: b-box 3V+, provided by my ISP (Mobile Vikings, subsidiary of Proximus, fiber connection).

I’ve switched ISPs several times: with my first ISP I had no issues at all, with the second I started noticing some minor problems (with a new modem provided), and now with my latest ISP (which is actually a subsidiary of my first and even uses the same modem model), the issues are back. Everything is fiber-based.

Since the modem’s Wi-Fi coverage is insufficient, I installed a TP-Link mesh network. Initially 2 Deco M5 (office and living room), both wired via Ethernet and set to Access Point mode. Recently replaced with 2 Deco X50 PoE (same configuration). My DECO system is in AP mode.

Usage:
Apple devices (MacBook, iPad, iPhone) connect via Wi-Fi only.
Desktop PC is connected via Ethernet to the Deco in the office.
Work laptop connects via Wi-Fi.

The issue:
For about a year, I’ve had problems accessing certain websites/services. On my Windows 11 PC: I cannot access sites like beatport, yahoo, twitter, ebay, etc. However, I can access sites like YouTube, Google, Facebook, etc. On my work laptop: I cannot access my virtual desktop via Citrix. On Apple devices: no issues, except for occasional switches between Wi-Fi and 5G on the iPhone.

From my research, this seems related to DNS/IPv6 issues.

Special note: I have a TL-WA850RE Wi-Fi extender connected to my Deco network (used to extend Wi-Fi for an outdoor camera). Strangely, when I connect my work laptop to this extender’s Wi-Fi, Citrix works perfectly. Same for my desktop PC: if I use the extender’s Wi-Fi instead of Ethernet through Deco, I no longer have issues. But since the extender is connected to my Deco system, I really don’t understand why this happens.

Tests already performed:

- Switch AP mode to ROUTER

- Factory reset

- Test with 1 Deco online

- Hardware replacement (migration to X50 PoE).
- Direct connection to the modem (Ethernet, bypassing Deco): everything works perfectly (no issues during 2 days of testing).
=> Connection through Deco (M5 and later X50 PoE): issues always come back.

From this, I conclude that the problem lies with my Deco units.

My question
Do you have any idea what could be causing this issue and what additional tests I could perform? I’d like to understand why my Deco units (M5 or X50 PoE) block certain access, while a direct connection to the modem works flawlessly.

Thanks in advance for your help.