After updating to the latest 2024.5 update, my local home assistant has become unusable (slow and things just not loading) but is fine via Nabu Casa (snappy and quick, everything working just fine).
CPU load, temps and RAM are all ok barely breaking a sweat, but I’ve noticed some higher CPU usage since the update, but not enough to kill the system.
Even starting Home assistant in safe mode locally doesn’t make a difference.
Again, accessing Home Assistant via Nabu Casa URL in a web browser works perfectly.
Take a look at your custom integrations and log files. 2024.5 added new debugging to identify custom integrations that are doing things incorrectly in HA. I’m willing to bet that you have a custom integration that is doing that very thing.
Update: rebooting the router worked for all of a few minutes. Again, just as described earlier, the local home assistant URL is struggling, but Nabu Casa is fine, with no significant system resources being used. i.e. CPU and RAM are idling at 1% and 20% use.