Re: ISP's DHCP is not functioning properly - ASUS router

My Asus RT-AC87R router was doing similar things and after trying everything under the moon I replaced it with a TP-Link AX11000.  It's a little overkill for most but it's working great.

I also had issues with my Arris SB8200, time sync, over range, etc.  I had Xfinity tech out twice, the 2nd tech noticed my modem only had one blue light on the front instead of 2.  Luckily I still had my old Arris SB6190 so we swapped it and both blue lights came on.