ARC "poor connection"

Verizon Modem (supplied by verizon/FIOS)
Ubiquiti UDM PRO Router
FIOS Business Internet Service
Modem in BRIDGE mode (I believe). All port forwarding done in router.
Port manually configured in router.
Static IP assigned to ROON Core. Settings for IP address & port in router match settings in ROON.
ARC settings in Core indicate “READY…Roon ARC can securely access your Roon Core”

ARC worked…briefly. Hasn’t worked in several months now.