SharePoint Online - Oslo Master Page doesn't apply to modern page (UI)

Question

I created a Team Site, I changed the master page to Oslo, but it doesn't apply when I'm displaying a modern UI page :

As you can see, I still have the navigation on the left (I can hide it but then people won't have the top navigation and will be stuck on the homepage).

Whereas, If I display a "Wiki page" or "Webpart page", the Oslo master page gets applied :

We have the navigation and search bar on the top now, which is exactly what I want.

Is this a normal behavior of SharePoint Online ? Can we have a modern UI Page having the Oslo master page applied within a Team site ?

Thank you and cheers !

Answer 1

Yes, it is normal behavior of sharepoint Online. Oslo and seattle master pages only affects classic pages. It would have any impacts on modern pages.

However, we could not change master pages in modern page. This is by design. Refer to this for more:

https://docs.microsoft.com/en-us/sharepoint/dev/solution-guidance/modern-experience-customizations-customize-pages