GT-BE19000 strange WAN behaviour

[Reservoir_Dog]

Hello all,

I just received this router. Set it up and it works fine. But, at night, i use the power switch to turn the router off.
So i started the router this morning and i got a red light. The 10G wan didnt connect, so i went into the router software and it states something with a fault with my DHCP server from my isp....
But the day before it worked perfectly. I rebooted the router, did restore to factory settings with the WPS button, still the same.
Then i tried something else, i just disconnected the cable, and put it back into the 10G wan port, and then it worked! I rebooted the router, again no connection, so pulled the cable out, back in and all is ok....
But im not satisfied with this behaviour, im in my return window, should i return the router? Next i tried the 2.5 WAN configuration, and with that port, i dont have this problem at all, even after reboot and powering the thing off....
Should i return it or not? BTW my isp speed is 1 gig down 40 mbit up cable internet (yes i know, belgium sucks)

Thanks