Scorer tablet count shows more tablets connected that really are

**Describe the bug**
The warning of multiple tablets connected to an Official Scorer position showing too many.

**To Reproduce**
Steps to reproduce the behavior:
1. Go to the official scorer page and select the match
2. Go back to the home page
3. Go back to official scorer page and observer warning of 2 tablets
4. Repeating steps 2 and 3 will make the count keep increasing.

**Expected behavior**
Count should only be active number of devices/tabs on that page, but it seems to be not cleaning up dropped connections correctly.

**Screenshots**

**Device (please complete the following information):**
- v8.0.0-beta.2

**Additional context**
N/A

Start by reproducing the issue from the official scorer page: select a match, return home, and reopen the scorer page while watching the tablet warning. Trace the connection lifecycle across navigation and verify that the count reflects only active devices or tabs after repeated visits; done means dropped connections no longer increase the displayed count.

Written by the indexing model from the issue text.