Windows 10 build 19603
Designer v 1.8.3.641
edit: also present on 1.8.4.650 beta
Steps to reproduce:
1. Document created with multiple artboards.
2. Image applied to one single artboard.
3. Image selected, create mask. Works as expected.
4. Apply fill gradient to mask.
Bug: Size of gradient mask applies to size of whole document. Expected behavior: Size of gradient mask should size according to parent image the mask is applied to.
Images attached for evidence.
Additional related bugs:
1. Click "Reverse Gradient" button in toolbar
2. Mask size changes to an unrelated size.