HA 2026.5 removed the hassio-main panel. Restart Core, Restart Supervisor, Reboot Host, Shutdown Host are gone from the UI. Built a replacement custom sidebar panel using the HA WebSocket API and native System Monitor entities. It willl make its way to github and HACS but wanted to get it out for those that need it while waiting for HACS Approval.
Its on github (careful the config.yaml is a little different) and it's in the queue to be released fully in hacs, but that can take months with their huge backlog.
The Supervisor Panel looks for specific entity ID patterns to find your CPU load sensor. I can only have so many automatically found and I think we've done a really good job of getting >90 percent to hit. If yours doesn't, the easiest fix is to make a template sensor. What will happen is the sensor will mimic your CPU sensor, but it will have a known name supervisor panel will hit on.
If your entity is sensor.processor_use, it won't be recognized automatically.
The fix is to create a template sensor in your configuration.yaml:
MAKE SURE YOU CHANGE THE "SENSOR PROCESSOR USE" TO YOUR OWN SENSOR
This creates sensor.processor_load which the panel will find correctly. Restart HA after adding it. This is listed in the github repository pjarbit, in the sensor panel readme.The example there is for disk use, but the CPU is the same, just need different terms to hit on.
One can enable the "real" core cpu-usage via the supervisor-integration.
The "cpu-sensors" from the system monitor integration are for the whole system, not for core only.
The search pattern should look first for: sensor.home_assistant_core_cpu_percent i think.