Good water with pH in the 5.0-5.4 range. But I did not check the pH during or after the mash. Next time I will do that for certain. I have the cheap pH strips, but that is good enough for now.
There's a red flag. Where is the water coming from? Municipal supplies will ALWAYS have pH > 7 because it's easier on the pipes. If you're using the cheap strips, that's probably the issue. They're wildly inaccurate. You can get 100 ColorpHast strips for ~$20, and they're well worth it.
The first things to check are still instrument calibration and crush though.
my water is good. Chippewa Falls spring water or St. Paul filtered tap water. Both have proven to be great for brewing. I had Chippewa Falls send me their water report. I said it was in the range of 5-5.4 only because of the cheap strips. Definitely not using my municipal tap water. I have friends in St. Paul that let me fill up when I'm in the area, or the spring water I can get at the grocery store.
my thermocoupler is good. calibrated with lab instruments at a club meeting last year. crush certainly may be a variable, but I err on the side of too fine, I think, so I'll have to wait to repeat a particular recipe with the crush as the only variable to check that.