"We agreed to disagree and that was it," Stills said after practice, according to Hal Habib of The Palm Beach Post.
Stills criticized Ross on social media last week after the owner hosted an event for Trump's re-election at his home in the Hamptons, which the 27-year-old perceived as hypocritical.
In the tweet, the veteran posted a screenshot of the mission statement for Ross' nonprofit, the Ross Initiative in Sports for Equality (RISE).
Stills said he texted Ross, who then called the wideout to talk about the disagreement.
"There's not much to argue about," Stills said. "He has his feelings about it and he stands firm in that and I respect that. But I disagree and I told him there's no hard feelings. There's no beef and let's win some games this year."
Stills also said he'll no longer be involved in RISE after Miami's first preseason game against the Atlanta Falcons on Thursday.
He opened up about stepping away despite a lauded history of social activism, saying he was turned off by "everything that's kind of taken place from the time of the first protest all the way to now."