He wrote: "If you're reading this ... I love you always.... unconditionally... not matter what."
The actor then told followers to "go stream" Demi's song 'It's OK Not To Be OK'.
He said: "They lyrics are incredible. Her voice is impeccable. Keep it at #1 forever. It's what Demetria deserves. I love you...
"Give her the Grammy she deserves!
"Demetria is THEE best female vocalist alive. And everyone should know it."
Max went on to suggest Demi wasn't behind the reports of their break-up.
He claimed: "She inspires me every day and is an INCREDIBLE human being. I know it's not her writing these stories. It's a machine. I love her unconditionally. Demetria I love you always and forever.(sic)"
On Friday, Max claimed on social media he had no idea about the break-up until he checked news articles online.
Following his comments, a source close to Demi, 28, insisted she definitely "made him aware" of her intent to move on from their relationship before the news was made public, but on Saturday night, the actor released another statement refuting those claims.
His statement, which was posted to his Instagram Story, read: "I was on the set of my new movie, 'Southern Gospel', with crew and cast members right next to me who literally watched me open my phone where I then opened a tabloid.
"This is the God's honest truth of how I found out about the ending of the engagement and have people from my film who saw the whole thing go down and helped me get back into character to continue my job."
In Max's original comments, the 'Young and the Restless' star threw shade at Demi for seemingly not telling him about her intent to end their romance.
He wrote: "Imagine finding out the status of your relationship through a tabloid ... While your in the middle of filming a biopic movie about a Pastor in a Christian Church whose intention of the film is to help people".
