Often it’s the other way around. First somehow they became off-grid (or on a finer grid), and later the grid is set to the most common 50mil [1.27mm] and symbols get aligned to that grid. Schematic symbols have a quite strict requirement for a 100mil grid between pins and sometimes (resistors, capacitors) shifted 50mil to the symbol anchor point. Maybe the new Grid overrides introduced in KiCad V8 changed the default so KiCad now puts things back on a 50mil grid.
A quick way to fix most grid problems in the schematic editor is:
- Set the grid to 50mil.
- Select everything, draw a box around the paper.
- Right click, and from the context menu select: Align Items to Grid.
In some occasions this can create shorts in your schematic, so watch out for that.