Hi Andrew, I too am using Unleashed with (4) x R500 A/P's, and I just logged into Unleashed Desktop successfully with Google Chrome Version 94.0.4606.81 (Official Build) (64-bit) on a Ubuntu based Linux Lite PC. I have been running Unleashed version 220.127.116.11.121 but noticed I now need to upgrade to 18.104.22.168.127. I believe that is the latest version that supports the R500 Access Points. I run my entire home on these Access Points (Mesh Mode) and have not had any issues logging in with any devices. I run FireTV sticks, Phones, PC's, Laptops, Tablets and Game devices without any issues. While I don't have any suggestions for you other than to simply shut it all down for 60 seconds and restart, I just wanted to let you know what I'm having success with at the moment to help you in your search for the problem.