Clients (over time) never renders, just spins

[RamSet]

See if this will fix your issue:

Fedora 27 FTLDNS upgrade, spinning arrows, Clients (over time) chart will not load

I don't usually like the nuclear option, but try this (it will wipe out any customizations you have in the Web interface): sudo rm -rf /var/www/html/admin sudo git clone https://github.com/pi-hole/AdminLTE.git /var/www/html/admin pihole checkout web FTLDNS