Yes I did slightly reduce the OPV until I got about 10 bar at the portafilter.

I asked because I had a similar problem with my Classic after adjusting the opv. Right after the adjustment I just couldn't choke the machine anymore on the finest grind setting of my grinder. Shot timings became very short and there seemed to be a greater flow of water/coffee out of the portafilter.
First I thought I broke the opv but after reading more about opv adjustment for vibe pumps I understood that by lowering the pressure you increase the flowrate. I was able to address these problems by changing my grinding burrs (because I had to go finer) and also by getting a better seal on the opv valve (the rubber seal that you see when you adjust the opv).

I don't know for sure if you're having the same problem, but maybe it's worth checking.

The rubber seal is on the low pressure side, so I don't think it'll be a problem.

Max flow through the pump will increase, but most of that will be diverted through the opv with a properly packed puck.

Based on my (admittedly limited) experience with the same espresso machine, similar OPV settings, and a naked portafilter, I'd guess the beans are either roasted too lightly or the grind is too coarse.

If you are already at 1 on your grinder, can you add a shim or something to space the burrs closer together at a higher setting, and adjust from there?

Also, can you remove whatever mechanism makes it a stepped grind setting or add more grooves to the stepping ring to get finer adjustment steps?

I have a continuously adjustable grinder (OE Pharos), and I've found that the spacing between getting a 60s 1oz pour, getting a 30s 1.5-2oz pour, and a blonde gusher is pretty small. Just past the onset of blonde gushers is when the naked portafilter starts spitting. With a New England or something on the lighter side of City roast, I haven't found anything I can do with puck prep (overdosing, finer grind) that keeps the machine from either being totally choked or channeling/spitting.

Ok thanks everyone for your suggestions. I "recalibrated" the Encore and that seems to have been the problem. It must have been the burrs "breaking in" because now I can get well-timed shots with no spraying.

In regards to the "freezing" issue, I simply meant in the past I have kept the beans in the freezer and only filled the hopper about halfway. I'd get a new pound of beans about every 2 weeks (when I buy them they are always within 1-2 days of roasting)