Bit of a wild guess here as well.
Could it be droplets of condensation in the in-feed tray forming and being picked up by the first part of paper that is slid over and into the first feed in rollers?
I run a Durst Printo and prior to that a Durst RCP20. I haven't done colour printing in a few years, but I still run B&W paper through my Durst Printo. I saw that kind of issue on both machines, mainly in summer time when I have air conditioning on in the darkroom.
The machine is running at a high temperature and the darkroom is around 23ºC The in-feed section of my Printo is not heated and with the warmth coming from the first bath, condensation occurs in the in-feed tray as it is sort of in the cool air flow from the air conditioner. Last week when doing B&W I ran the bath at 34ºC - 35ºC and with the temperature differential of the room I get plenty of small droplets of condensation on the in-feed tray as the air conditioner is on due to summer heat. I regularly wipe the in-feed tray, sometimes I cannot see the droplets of water, but using a fine closely woven linen tea towel, I can feel them when wiping.
Mick.