Help request for rats peeing through cage

I have 3 female rats, and I’ve recently been struggling due to one or more of them peeing all over the cage as well as through the bars onto the floor.
their Cage is a 4 foot tall bird cage that has wood platforms and various other climbing things going up the sides and middle for them to climb. It has a handmade cloth liner that goes up the edges about 2” in the bottom.
I put a few layers of news paper under the liner.
i then give them cut up pieces of news paper and scrap fabric for them to make their bed with.
I also have a litter tray that I use cat litter in and they use it pretty much always for pooping but won’t pee in it.

So my problem is that they’re peeing on everything, and not just scent mark peeing, the platforms will be dripping after just one day, and they’ve decided recently to pee through the bars onto the floor, so now there’s a puddle every day that I have to clean up.
They also have hammocks that they sleep in that they also pee in.
I’ve had them for about 3 months and they’ve only just started peeing through the bars in the last week or so and everywhere else in the last 2-4 weeks.
There’s nothing I can think of that has changed environmental wise, and I take them out every day for 1-5 hours, so I give them quite a bit of attention.
I’m really at a loss for what to do.
I got them to help with my mental and physical health issues since I’ve had 3 previous rats that really helped me, but I’ve recently (after getting the rats) been progressively feeling more and more sick after little movement so cleaning their cage is hard for me already but I was managing until everything started getting soaked. I’m really attached to them and don’t want to have to rehome them due to this so I’m looking for any suggestions as for what to do.
I never see them pee so I’m unable to move them into the litter tray to train them that way.
And will be putting a rock in their litter to see if that helps but am looking for other suggestions in the meantime.