Multiple regions/labels selection and drag, not working

**Describe the bug**
I am labeling gestures. On a video timeline, it appears I cannot select multiple regions with the 'shift' shortcut (as in the documentation). Only 'ctrl' works, meaning that I need to select thousands of labels one by one, which is not sustainable.

Additionally, when multiple regions are selected, I can't move them altogether. Only the region where the click happens gets dragged.

**To Reproduce**
Steps to reproduce the behavior:
1. Go to a video timeline to label a gesture. Add 10 regions randomly.
2. Issue A: Try to select more than 2 regions at once.
3. Issue B: When multiple regions are selected, try to drag them all at once.
4.
**Expected behavior**
- When using the 'shift' shortcut, I expect to be able to select large groups of regions. Not one by one (like 'ctrl').
- When multiple regions are selected, I expect to be able to drag them altogether, at once.

**Screenshots**

**Environment (please complete the following information):**
- OS: Windows 10 (The issue is not only on Windows. It's been tried on multiple iOS as well)
- Label Studio Version 1.12.0

**Additional context**
I am labeling 3 camera angles of each gesture. The various footage do not have the exact same timestamp. Therefore I want to copy-paste the regions from one initial angle to the other two, then drag the regions at the right timestamp.
Selecting and dragging regions one by one is not sustainable.

Thank you.