This is an issue on Nova and latest Android. To solve this you have to:
- Ensure you are running 3.78 version (latest), 3.77 has a bug in autoscaling
- Ensure Widget Settings → Scale mode is set to LOCKED
- Then either click on the widget to open the editor by assigning open editor to the root OR add a new widget and resize it before editing
The problem is that Nova is not reporting correct widget size when using the “new” widget “sizes”, you can report this to them if you want also “Autosize” to work.