RODI problems

[mseepman]

So I have a BRS 75gpd 5 stage plus RODI system. I've had it for about 3 years and up until about 6 months ago, it worked really well. During those years I have kept the unit maintained and clean. Regularly changing the prefilter and carbon blocks as needed. My TDS through this has stayed around 8 out of the RO and 0 after the DI.
6 Months ago the unit production just dropped off. I replaced the prefilter and then the two carbon filters thinking maybe something was plugged. That didn't fix it. I got a new flow restrictor as I know they can fail, but nope. I removed my auto shut off valve and the check valve in case they had failed...nope. Yesterday I got a new RO membrane and put it in place....no change. I removed my auto flush kit yesterday in case something there was causing issues...nope, no change.

I'm at a loss. I've replaced pretty much everything. When I changed the membrane, I cleaned the housing well. What else could I be missing. My pressure isn't what it should be...but it's just shy of 50psi...which is what it was all through those years of use. Right now, it takes about 10 hours to fill a 5 gallon jug...so I can't waste the water even trying anymore.