The post has been removed from Instagram but was uploaded on TMZ.
The video appeared to be filmed from the 22-year-old's cellphone.
"We are aware of the report and have addressed it," the team said, according to ESPN's Jamison Hensley.
The Ravens selected Jackson with the No. 32 pick of the 2018 NFL Draft. He started seven regular-season games last year.
Baltimore officially traded previous starting quarterback Joe Flacco to the Denver Broncos on Wednesday.