My apologies if this has been called out before; or if I've misunderstood the input form.
The problem lies with 'Backgr transparency' and 'Text alignment'.
'Text alignment' appears to be disabled if 'Backgr transparency' is not 'Transparent'

Version 4.44-64 bit, run on Windows 10

1A. Edit>Insert Text>Add overlay text to image
Backgr transparency: NONE
Text alignment: Left
Result: text centers at top middle (?: label should be at top left)

1B. Edit>Insert Text>Add overlay text to image
Backgr transparency: SEMI-TRANSP
Text alignment: Left
Result: text centers at top middle (?: label should be at top left)

1C. Edit>Insert Text>Add overlay text to image
Backgr transparency: TRANSPARENT
Text alignment: Left
Result: text at top left (OK)

In addition, with Backgr transparency at TRANSPARENT, 'Text alignment' works properly with choices of 'center' and 'right'.