IPv6 Ping (ICMP)
Pinging a monitoring host using ICMP6 doesn’t currently work due to an issue in our virtualization tool. Connecting to IPv6 hosts DOES work, so you can use TCP port monitoring or HTTP requests.
Slow Dashboard and Operations
Uptime Kuma uses SQLite to store monitoring data. No other databases are supported. This can make it slow if you monitor at very short intervals and keep the data for a long time. More here and here.
Solution is to reduce monitoring history and frequency, as described here or add more CPU cores to the pod.
You may see offline monitors while either using the Shrink Database feature or reducing the number of days to keep. This can last for 5 to 10 minutes, depending on the data size.