Users of Whoop’s fitness trackers have been reporting that their Whoop MG fitness trackers are turning unresponsive, in some cases within under an hour of setting them up. Now, the company is apparently replacing the trackers, in some cases before the users even ask, TechIssuesToday reports.

Launched alongside the Whoop 5.0 earlier this month, the Whoop MG (which stands for “Medical Grade”) comes with EKG capabilities and blood pressure insights and requires a premium Whoop Life subscription that’s $359 per year. Users started reporting issues with the tracker almost immediately.

On May 11th, a user reported in the Whoop community forum that their MG “stopped working overnight after working for 8 hours. No green light, no bluelight nothing. It won’t now pair with the app.” Others replied to say the tracker failed even sooner for them, with one person reporting that it went inert after just half an hour of use. Some also report that their 5.0 has failed.

It’s already been a troubled launch for Whoop. Earlier this month, some users were outraged when Whoop said they would need to add another 12 months onto their memberships to avoid the upgrade fee for the Whoop 5.0. Previously, users only needed to have 6 months left on their subscription to get a Whoop 4.0. The company soon walked its new terms back, posting on Reddit that those who had at least 12 months left would be eligible for an upgrade.

Whoop did not immediately respond to The Verge’s request for comment.