i have ftth connection with deco m4 .... some engineer came from isp with their modem for test and it came out that there is serious problem with the update ..... firmware 1.5.4 i downgraded to 1.5.2

Frequent packet loss on the Deco M4. No packet loss when connected directly or connected through another router. Router LED flashes red when packet loss happens 1. Yes both the Deco M4 units are turni