In the Add Tests To Test Execution screen, when filtering issues by labels, when starting to write labels, the already selected ones are being overridden

Description

In the Add Tests To Test Execution screen, when filtering issues by labels, when starting to write labels, the already selected ones are being overridden.

How to reproduce

1. Go to a Test Execution and click on the Add Tests button
2. Select Existing Tests
3. Filter tests by labels. First, open the dropdown and select some labels.
4. Then start writing another.
5. The previous one is removed.

Actual result/Attachments

The previously selected labels are removed.

Expected result

All labels should be kept.