Hi @pjonason there are no changes in 3.4.1 respect to 3.4.0 related to machine listing and UI-related queries.
When you upgraded to 3.4.1 it’s expected to have high cpu usage for a small period of time because some cleanups are run. But after that, you should expect MAAS to be much faster according to our investigation !Action required: this cleanup might speedup your MAAS (3.4.0 and below) environments
Do you experience peaks of CPU usage periodically? Do you have monitoring enabled so that you can provide some numbers and graphs?