Reproduction steps:
1. Open the attached project "Tool Handle Position.zip"
2. In the Toolbar toggle "Toggle Tool Handle Position" from "Center" To "Pivot"
3. Observe the "Pivot" button icon and switch back to "Center"
4. Go to Edit/Preferences/UI Scaling
5. Set the "Use custom scaling value" to 125%
6. Close and reopen the project
7. In the Toolbar toggle "Toggle Tool Handle Position" from "Center" To "Pivot"

Expected result: The "Pivot" button icon appears with no issues
Actual result: The "Pivot" button icon appears distorted

Reproducible with: 2021.1.0a1, 2021.1.0a7
Not reproducible with: 2019.4.15f1, 2020.1.14f1, 2020.2.0b13
Couldn't test with: 2018.4.29f1 (No UI scaling feature)

Notes:
- The issue will only reproduce if the UI Scaling "Use custom scaling value" is set to 125% or by having Windows Scale Layout set to 125%