I HAD this router. POS all around. Even the russian pavalan third party firmware can't fix it.
If you want to stick with the official firmware, this was the only reliable one not to get WAN disconnect
DOWNGRADE your firmware to this one:
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202.221.139.247/pub/asus ··· 4342.zipAddl benefits to this downgraded firmware is wireless signal strength boosted (this is a long story).