Count current playback rather than profile icons
Looke’s terms describe five authorised profiles but limit simultaneous viewing to three users. A household can therefore create a fourth or fifth profile without gaining a fourth concurrent screen. Profiles organise viewers; they are not tokens that each add a playback allowance. Treating profile creation as an upgrade would send troubleshooting in the wrong direction.
Work through the fourth-screen example
Suppose three people are already watching and a fourth chooses an otherwise unused profile. The new profile does not remove the three-stream condition. First determine whether the other sessions are actively playing, rather than counting how many profile names appear at sign-in. If playback still fails after another viewer has deliberately stopped, preserve the exact error and timing for support instead of repeatedly making more profiles.
The remembered-device list answers a different question
The help centre says there is no fixed limit to devices used with the account, while current playback is capped. It places the device list and removal controls in the computer account area, and says mobile users cannot view or change that list there. A long list of remembered devices is consequently not proof that they are all consuming streams now. Use it to review sign-ins and remove unrecognised devices when appropriate, while keeping the live playback investigation separate.