Grande and the 19-year-old comedian first dated in August 2012 and were together for around a year before separating.
The 'Problems' singer felt Brooks was not supportive towards her, when she tried overcoming her grandfather's demise, reported Us magazine.
"It has not been an easy few months. Jai just wasn't as supportive as he could have been," a source said.
The 21-year-old star posted a message on her Twitter page yesterday asserting the fact some people had not been there for her while she grieved her grandfather.
"I thank everybody who was here for me when I needed them as the ones who weren't really broke my heart," she wrote.