Thanks for the prompt reply.
Im using a Surface Pro 7.
When using Evernote legacy I could have a 50/50 split in windows 11 (ie browser on left 50%, evernote on right 50%).
When using Evenote 10+ Evernote wont allow a 50/50 split. In other words it wont default below 60% of the screen (ie browser on left 40%, evernote on right 60%).