Still Spell still failing ASF checks

[Sapper Woody]

I have only noticed this on one spell, Magic Circle against alignment. But it has failed do to Arcane Spell Failure three times now, despite me having Auto-Still 0-3. It is a third level spell.

It seems to work fine when it is slotted as a still spell, but not when it is slotted as a regular spell with Auto-Still.

Thank you.