After a product to re-waterproof my shoes.
Mine leaked today but to be fair it was chucking it down

You sure it was through the fabric and not the large hole the leg sits in? Mine let water in eventually through the top socks acting as a wick.
Try one of the Nikwax or Grangers waxes to improve resistance.

Never re proofed mine, they are gore tex lined so shouldn’t make a difference to their waterproofness. Have found that if stepping in deep puddles water can come in over the tounge though, or as mentioned above, via the ankle cuff which isn’t waterproof

I noticed today that my toes were wet before they filled up with water from the top.

I use dubbin on mine, also makes them softer, especially if I have had to use the radiator to dry them.

If they’re real leather get a couple of disposable nappies, turn them inside out (the nappies not the boots) stuff them into the boots, leave them somewhere warm overnight to dry out then give them a good dose of dubbin.