Miley first bagged the Best Pop Solo Performance Award for her hit song "Flowers" before the song later cinched the Record of the Year trophy -- and while she thanked several key people in her life onstage, she notably omitted mention of the iconic country musician.

The former Disney star went through the laundry list of people she wanted to thank -- her team, everyone onstage with her, her BF Maxx Morando, as well as her mom, Tish Cyrus, and sister, Brandi Cyrus -- but Billy didn't get a coveted shout-out.

The snub was even more pronounced as Miley made a concerted effort to ensure she didn't overlook anyone ... turning to her team behind her, asking: "Anyone else? Your wife, your fiancée, all the people that we love. Thank you all so much."

Even her undergarments got a playful shout-out, as she joked: "I don't think I forgot anyone. But, I might have forgotten underwear. Bye!" ... but as for a mention of Billy? Nada!

The omission may be a wholly innocent slip of the mind or may allude to an extension of reports from 2022 that Miley's relationship with Billy was strained following his divorce from Tish ... who attended the Grammys with her daughter.

Remember, Miley once shared a special bond with Billy who played a pivotal role in launching her career through "Hannah Montana" -- they shared the screen on all 4 seasons of the TV show, and the subsequent film.

If there is family tension, Miley didn't show it though -- she was glowing during the rest of her acceptance speech, saying: "This award is amazing, but I really hope it doesn't change anything because my life was beautiful yesterday."

Miley added, "Not everyone will get a Grammy, but everyone in this world is spectacular, so please don't think this is important, even though it's very important."