The New York Times ran this story in April (before George Floyd)
As the coronavirus continues to spread, infecting and killing African-Americans at disproportionately high rates, black men find themselves facing two concerns: the virus and those who see their covered faces as threatening.
It later notes this
In March, before the C.D.C. issued its recommendation, two black men in surgical masks filmed themselves as a police officer was kicking them out of a Walmart in Wood River, Ill. In the video, which has been viewed more than 250,000 times on YouTube, the officer can be seen following them.
Chief Brad Wells of the Wood River police said in a news release that the officer in the video “incorrectly” told the men that a city ordinance prohibited masks.
“This statement was incorrect and should not have been made,” Chief Wells said. “In fact, I support the wearing of a nonsurgical mask or face covering when in public during the Covid-19 pandemic period.” The men have since filed a complaint, and an internal investigation is underway.
A piece in Vox notes this
Not wearing a protective face covering has gotten a black man into trouble, too. A video out of Philadelphia earlier this month shows a black man being forcibly removed from a public bus by at least four officers just a day after the city’s transportation authority required that all riders wear face coverings while on public buses, trolleys, and trains. The video, which shows the police first swarm the man then yank him from the bus, is especially jarring during an already tense public atmosphere. Following the incident, the transit authority announced that face coverings were no longer mandatory.
The problem is neither piece concretely ties this to profiling. NY Times has this part
It is unclear how many profiling incidents there have been since the C.D.C. issued its recommendation earlier this month. Melanye Price, a political-science professor at Prairie View A&M University, a historically black university in Texas, said the pandemic and the C.D.C.’s mask recommendation, however well-intentioned, could put African-Americans at greater risk.
And Vox caveats
So far, the reports of racial profiling are anecdotal and there are just a known few. But did the incident occur if it wasn’t caught on camera?
In other words, the evidence to date have been mostly anecdotal, with a few incidents that police escalated needlessly. I can't find any evidence of any broader problem from serious reporting (NYT would not be shy about that if there were).
Why did Lincoln County, OR exempt blacks?
Apparently they did so solely based on the reporting to-date
"We included the protections for those within our communities of color who historically, and often personally, found themselves the victims of harassment and violence," the Lincoln County Board of Commissioners and County Management team said in a statement Wednesday evening. "We are shocked and appalled at the volume of horrifically racist commentary we have received regarding this policy exemption."
The exception, local officials said, was well-intentioned — a way for people worried about racial profiling to avoid that by having the option to not wear a mask, Lincoln County Commission spokesman Casey Miller.
There's no mention anywhere that a complaint sparked this. The board was apparently trying to err on the side of caution.