Blue stains can imply developer carryover into the blix, or fogging. Though you don't have a safelight, that doesn't mean your darkroom is safe - RA4 is pretty sensitive stuff so I would suggest doing a safety test by progressively covering a sheet with hard-edged things (coins, tanks, whatever).

To prevent carryover, the recommended way is to use at least one of a stop bath and/or rinse between developer and blix. My process looks like markbarendt's though I give it at least 2:00 of rinsing (as per Ektacolor specs) and 4 changes of water in that time.