I presume the top pop bumper isn't working either.

See the pattern in the J4 pin signals:

PPPP
BBBB
3210
==========================
0000 ..x.. 4 drop target reset
0001 ..... 3 drop target reset
0010 ..x.. Inline drop target reset
0011 ..... Saucer kickdown
0100 ..x.. --
0101 ..... Knocker
0110 ..x.. Outhole
0111 ..... Saucer kickup
1000 ..x.. Single drop target reset
1001 ..... Pop bumper left
1010 ..x.. Pop bumper right
1011 ..... Single drop target pulldown
1100 ..?.. Pop bumper top
1101 ..... Slingshot left
1110 ..x.. Slingshot right
1111 ..... N/A

Yes, from the binary table above it's solenoid select line "PB0" that's open circuit (Blue-Yellow wire from MPU J4-4 to SDB J4-6). The default state of the select lines on the solenoid driver board are high, the MPU board pulls them low. The solenoids that aren't working require PB0 to go low which isn't happening.
Having said this you should be noticing when the solenoids you listed aren't working, wrong solenoids should be activating. For example when the "Inline drop target reset" should be activating, the "Saucer kickdown" will instead activate.

If you're bulletproofing the displays, change the 100k resistors in the digit drive circuits: R1, R3, R5, R7 R9, R11, R58
They're underspec and run close to their wattage rating and eventually fatigue and fail. You can measure them in circuit to see if they're still in spec.
We replace them with higher wattage versions.

I'm surprised this moisture damaged tilt board problem in high humidity doesn't come up more often. Besides having the issue myself (my tilt boards were factory plywood), you're only the third pinsider I've helped with it over the years.

BTW, game's looking great!