I have a basic query but could not find a definite answer on the internet. I am currently running a campaign for the main website of a big education brand and they also have a secondary learning website on subdomain, and I want to add sitelinks of subdomain to the campaign, but I am not sure whether it is allowed or not.

The brand I am running ads for is https://www.rauias.com/ and the secondary website is https://compass.rauias.com/ branded slightly different in a subdomain, so should I add the sitelinks of Compass to the main campaign?

Also one more silly question

My Max Conversion search campaign gave me this status today.

"Learning (composition change): Campaigns have been added to or removed from the bid strategy. Google Ads is now adjusting to optimize bids.

5 days left for learning"

What does this mean exactly? And Why does it reenter the learning phase whenever I make a small change?