spletsto

I recently grain filled espave using aqua coat (apply, scrape, sand repeat). I then laid down 4 coats of sanding sealer and during my level sanding I noticed a few spots where I didn't completely fill the grain. Can I re-apply grain filler at this stage even though I have the sealer down or do I need to sand it all back and start over? sorry for the basic question pretty new to this. thanks!