Thanks for the update. I actually purchased the XR500 to remove a CenturyLink router in concert with a TP-LINK, so that I could have one router own it all. The testing you referred to back in late July, is that still underway? Assuming that's not the version I am on...?
Facing a similar issue with 18.104.22.168 where I am unable to access port 5000 on my Synology Diskstation. I'm on CenturyLink with VLAN tagging enabled and this is an absolute pain as I'm also unable to back up my MacBook via Time Machine as it never connects. What are next steps...?