I believe I saw this movie on Tubi. I think all or most of the characters were white. It had at least 4 or 5 college students going to a cabin or something like it. At least 2 guys and 2 girls. The place they were at had hills because at the end I remember that the main girl had to run up and down them. I think it involved an alternate dimension or parallel universe or portal of some sort.
The main girls sibling was missing (?). I am not completely sure of this plot point.
They had traveled through the woods and went through to some sort of portal they could not see but ended up in a world that was violent or caused violence??? I believe none of them could use their phones and did not have service when things went awry.
Near the end, one of the male characters was chained up outside and a female character ended up hitting him with an ax/knife. He was trying to get out of the chains and they spoke for a bit. There was paranoia due to the guys actions. They fought and I think one or both were injured. I believe both characters were white and had dark hair.
At the end, the main female character had to go back through a portal(?) and was warned she had to leave through the portal at a specific point or time or she would be stuck there. This portal was in the woods on a trail. She was warned by an older man. The older man was either by himself or with one other younger person. They knew about or kept track of this portal. She went back to save her sibling or one of the other characters who was her friend.
I thought the movie might have been Lake Artifact (2019) but it’s not. I think the movie might have been filmed 2014-2018. At the very least it was post 2010s. Would love to know if any of you know it because it is driving me crazy.
