RBE871 slow speed

Hi CrimpOn and FURRYe38,

today I made a few tests.

Looking at the Advanced Tab on the web interface the WAN Port speed was 100M/Full, as supposed. The Orbi was plugged into a RJ45 wall socket via a CAT7 patch cable. 

1. I tried different RJ45 wall sockets around the room - still 100M/Full - While, plugging the MacBook directly into the exact same RJ45 wall sockets the speed is 1Gb (960Mbps testing the wired connection by Oakla Speedtest). Does the MacBook adaptor negotiate at 1Gbps while the Orbi WAN port negotiate at 100Mbps? It seems like that.
2. I tried plugging/unplugging the patch cable into the RJ45 was sockets, into the Orbi WAN port and even into the FritzBox! 5590 router - still 100M/Full
3. I disabled the Traffic Meter - still 100M/Full while Ipv6 was already disabled and Armor is enabled but I couldn't found how to disable it.
4. I unplugged the wall wart in order to power cycle the Orbi871 - still 100M/Full on the WAN port

Then I made exactly the same thing I've already done last week: from the web interface I restarted the Orbi 871. Bingo! 

For the second time suddenly the Orbi WAN Port showed 1000M/Full and accordingly (wired or wifi) started to go at 960mbps speed.

It seems that the restart command via the web interface can repeatedly  "unlock" the WAN port from 100M/Full to 1000M/Full. More than a tiny wire problem along the RJ45 ports or jacks, it seems that the Autonegotiation is influenced by the Orbi's WAN port in some way. Without a physical action to cables and plugs, the restart process launched from the web interface changes the WAN port speed.

Pretty odd but that is what happens. Again. 

Now the speedtest is showing around 960Mbps consistently... can't say if this scenario will last forever - I'm afraid in a few day I will fall back in the previous slow WAN port scenario.

Any idea?