"dadiOH" wrote in :

Neither have I and oil base stain would just dissolve any residual
body oil. Never used water base, is it possible that would be blocked
by body oil?

That's why I was thinking glue residue, from the manufacturer.
I know I've had plenty of "dammit" moments when I've stained
and noticed a glue spot near a joint, that I didn't catch
when sanding.

John