ZyXEL DX3200-B0 VDSL Modem Router

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Hi there,

I am using ZyXEL DX3200-B0 VDSL Modem Router in my home.
I have an issue, DSL link always active, so i have internet, but sometimes my connection LAN/Wi-Fi is down/drop for 3-4 second. Then my connection is turn back again. i am using 2.4 ghz and 5 ghz Wi-Fi bandwith together. what could be causing this problem? Please help, thanks.

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