Chris Brown and Karrueche Tran gave Team Breezy nostalgic vibes of yesteryear when the former lovebirds were spotted together at Coachella ... and that's exactly where the vibes will stay.

There will be no romantic reunion!!!

Sources with direct knowledge tell TMZ … the singer-songwriter and “The Chi” actress bumping into each other at Coachella was nothing more than a friendly surprise -- and it wasn't the first time since their 2017 split.

We're told they’ve remained cordial through the years since their breakup, and when they see each other in public, neither one is above saying "Hi" to the other.

We're told there’s no bad blood ... but no, they're not getting back together.

Our sources say they’re not in touch regularly and only speak when they run into each other in public -- like at a festival attended by hundreds of thousands of other people.

Chris told Kai Cenat a few months ago he successfully juggles multiple relationships but fans seem to believe he'd clear the schedule for another crack at Karrueche.