OS:Windows 10 x64
When putting a drop-shadow onto text, the controls produce unexpected behaviour:
There may be two bugs here, but they seem very closely related
To reproduce:
1. take any plain image, or create a new one filled with a pale coloured background (640x480 is fine, but also observed on far larger images)
2. select image and "Batch Convert"
3. Add Action -> Add->Text (enable)
4. type a few random characters as the text to insert;
5. Position tab: units: % height (does not matter); Position: center (does not matter); margins:0; rotation:0
6. Text tab: Font: any; Size: 10%; alignment: left color:white; opacity:100; aa: (don't care)
7. Aspect tab : all off
8. Shadow tab: activated: yes, offsets: 0, blur 5
At this stage the shadow should appear symmetrically around the letters, and it does.
Now:
- apply some "X" offset and note that the shadow moves vertically;
- apply some "Y" offset and note that the shadow moves horizontally;
Second part: Reset Offsets to zero and return to "Text" tab.
- select alignment: center; Expect: no change; Actual Result: shadow jumps some distance (about half a font height) below and to the right
- select alignment: right; Expect: shadow centred on text; Actual Result: shadow jumps some distance to the right
Thanks to your detailed description I can reproduce