Recently my Jenn-Air SVE47500B's cooling fan has started turning on when the oven temp hits 225°F. For the last 3 years (as long as we've owned this house), this fan only came on when the oven hit 500°F, and would cycle on and off at that temp. This is not the downdraft fan, and it is not a convection oven. This is the fan in the back that blows into the space between the oven and the stove top. My wife said it showed an F4 error code once as well, but I have not seen this myself.

I feel like there's more clicking coming from the relays while it's heating than there used to be, though that may just be me misremembering things.

I also stuck a thermocouple in the oven last night while running it, and it seems to be about ~45°F hotter than the display reports. No idea if this is new behavior or has always been this way.

Things I've done:
A few months ago, I replaced a cap on the display board because it was dim and was able to fix that. Thinking this may be a similar issue, I replaced the rest of the caps, except for the 22uF as I didn't have one on hand.

I checked the high temp switch above the oven, and it had 120V to Gnd on each side, both when the fan was off and after it turned on.

I checked the oven sensor (temperature probe), and it has a reasonable resistance of around 1100 ohms.

I pulled the relay board to inspect it and saw nothing obviously amiss. I replaced the 47uF cap since I had one handy, but left the 3300uF alone. I reflowed the pads on J10 (thermistor input) in case it had cracked.

None of this has helped.

Any ideas where to look next?