Voltage divider for monitoring solar/battery
I ran your resistor values and voltages through this voltage divider calculator.  It comes up with different values than you got.
For 25V, 220K and 68k, it says the output voltage will be 5.9V compared to your 3.16V.
For 4.7V,220k and 440k, it says the output voltage will be 3.13V compared to your 3.2V (probably differences in rounding.)
Incorrect version (I had the resistors reversed): For 4.7V, 440k and 220k, it says the output voltage will be 1.5V compared to your 3.2V.
Besides whatever problem there are with the calculated values, you've made your calculations without regard to the impedance of the ADCs.
In the RP2040 datasheet, you will find this notice on page 581:

The  ADC  input  is  capacitive,  and  when  sampling,  it  places  about  1pF  across  the  input  (there  will  be  additionalcapacitance from outside the ADC, such as packaging and PCB routing, to add to this). The effective impedance, even when sampling at 500kS/s, is over 100kΩ, and for dc measurements there should be no need to buffer.

There'd be no need to buffer normal, low impedance signals.
Your voltage dividers are at or above the impedance of the ADC input, however.
You need to either use smaller resistors to keep the impedance of the voltage dividers much lower than the input impedance of the ADC, or you need to use a buffer amplifier between the voltage divider and the ADC.
If the RP2040 has selectable conversion time, then you could probably get away with the high value resistors - a very long conversion time effectively raises the input impedance.

You could switch the voltage divider on and off when measuring voltage like this:



simulate this circuit &ndash; Schematic created using CircuitLab
A high on the GPIO turns on the voltage divider, a low turns it off.  When off, you only have the (very low) leakage current through the MOSFET instead of the full current through the low impedance voltage divider.