Screenshot comparison
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I think that is inconsequent, rotation angle is from drawing 1, but base point is base of complete group?
Select all line drawings
Menu 'Format → Position and Size → Rotation
> shows 90° due to Comment 2
Modify rotation angle 90° → 135° [ok]
> Complete "group" rotated around center marked by cross center
Bug 122417 - Rotation angle for grouped objects or multi object selections shows rotation angle of first drawn object for group