Fresh Install - Synology - Getting Logged out

I’ve installed HA on my Synology DS1817+ in Container Manager. All running and I’ve set up my first integration, but any time I navigate between integrations or devices, or try to make changes, it logs me out, which is making learning the platform impossible. Debug tools suggests my very short configuration.yaml file is OK, I’m not sure where else to look. Have tried another browser. Searching for the issue is drawing blanks. Any pointers would be appreciated!

On the login screen, did you select keep me logged in ?

Indeed, yes - this does feel like some other issue though. For example, if i try and add a new dashboard, boof… logged out.

Thanks