I've been using my Compak k10 with Scarlett City Warp Drive (which I highly recommend, btw) for 6 or 8 months, and everything was dialed in perfectly and consistently. Week to week, batch to batch.

Recently, the timed grind on the grinder has been under-dosing by 3-4 grams, and my extraction times are all over the place shot to shot. I increased the grind time to get back to 19-20 grams (which over the last few weeks has added a second to the grind time.) Even with added times, I am getting inconsistent doses. And have been adjusting the grind as best I can. Now, the grinder is set ~200 and when it was running perfectly, the grind setting was around 150. These are relative numbers on the machine's digital display. I'm using a short hopper which is consistently half-full of beans.

I am at a loss as to why things changed and keep changing. I'd like to be able to hit "reset" to get back to my preferred 18 grams in, 30 grams out in 28-30 seconds from pulling the lever.

I clean the grinder on a regular schedule with Grindz and run some crap coffee through afterwards. The burrs are broken in. The workflow is as consistent as I can manage: dose with funnel, WDT, tap and then tamp. VST basket. Can't suggest I get a better grinder....

Looking for ideas...Could the coffee blend and consistency be off? I haven't asked the roaster, but imagine she'd tell me everything is the same.

Are you single dosing ? If you are not the varying grind volume could vary depending on the amount of beans in hopper. A full hopper would add greater downforce vs a low filled hopper.
I would suggest making a note of hopper level and see if this relates to your grind vs timed grind amounts.

Warp Drive is indeed yummy. Jen uses at least 5 different beans in it. Your routine sounds precise and you've got good tools. I think what you're seeing is just the effects of weather changes here in the bay, on deeply roasted, low mass-high volume coffee (most susceptible to static and moisture changes).

If it were me, I'd either accept that I'm going to see some variability in timed doses on a coffee like this, or I'd start single dosing with RDT. I've used this espresso blend several times in the past and I used to own a few different iterations of the K10 grinder.