The singer was at Sunday's big match -- where the men's singles final between Djokovic and Alcaraz is going down -- and she was ringless on a very specific digit. This isn't the first time Ari's been out without her bling ... but this one's a big deal since it's a high-profile event.

She was seated between two celebs -- Andrew Garfield and "Bridgerton" star Jonathan Bailey -- with no sign of her husband Dalton Gomez. That itself isn't notable, seeing how the guy tends to stay out of the spotlight, but the fact she continues to ditch her ring certainly is.

Rumors have been swirling for months that their relationship might be on the rocks -- due, in part, to AG's bare finger being exposed time and again in IG posts she herself publishes ... although, this is something she's explicitly written off in the past as BS.

However, we've been told by sources with direct knowledge that Ari and Dalton have, in fact, had marriage trouble of late ... including a rough patch a few months ago. We don't know what their status is now, but what we do know ... Ari's been away from home/busy at work in the UK -- working on her new movie, 'Wicked,' alongside Cynthia Erivo for a while now.

Of course, Dalton himself has deleted his Instagram account entirely ... just another element that's sent her fans into a frenzy. And yet, Ariana recently telegraphed that things are fine.

On their 2-year anniversary this past May, she posted a photo of her and Dalton kissing at their wedding, writing the number "2" as well as "3.5 together," with an accompanying "I love him so." So, on the face of things ... she's tried projecting a loving bond between them.

The couple got hitched in a private ceremony in Montecito in 2021. Dalton isn't nearly as famous as her -- he's a high-end real estate agent, and not much is really known about him.