Are you testing the filtered water before it touches the bucket? If not it could be dissolving precipitate from the bucket.
Make sure your using cold water,.. Hot water can damage the RODI.
next thing would be to look at your lines,.. How old are they? If they are too old they may have mineralization on the inside.
If your filters are only a month old it should still be 0TDS unless you make some serious water or have a water source loaded with dissolved solids.
A month seems okay for that filter to turn brownish,.. That happens. Does your RODI unit have a flushing system? If so I would suggest flush the unit out.
last thing I would try is turning on the source water with the product line closed,.. This will build up the pressure, then open the flush valve if you have one,.. If not open the product line to release the pressure hopefully dislodging and buildup.
Good luck!
