Litter training advice...

I have a question regarding my two Netherland Dwarf house rabbits and their litter training. We have had them for a year and a half now and we got them when they were both very young. We litter trained them from the beginning, and they have free range of the whole house, with a small comfy litter box with yummy hay as litter, which we change daily. We have moved to a new home since getting them, but that was back in May of last year and they have adjusted well to their new surroundings. Recently, within the past month, they have been peeing and leaving pills in a corner in the bathroom, and a couple of nights ago we found a bunch of pills and pee in another corner. We clean it up as soon as we find it, and even tried cleaning with white vinegar, as we have heard the smell can dissuade them from peeing in that spot again, but this doesn't seem to be working. Is there a reason why they would suddenly go untrained? Is there any way we can train this out of them? Moving their litter into the spot in which they are peeing would be unlikely to help, since they tend to train to the location rather than the litter box, as we have discovered in the past. Any help would be so appreciated, thank you!

Are they neutered/spayed?

We have one buck and one doe. The buck is neutered, the doe is not spayed.

I'd suggest getting her spayed, ovarian cancer is very likely in female rabbits and it will also cool her hormones which could be part of why she is pooing everywhere and the male then joins in!

If the rabbits poo in the same area, consider putting another litter tray down. If there is no hay available to them as they are pooing then this may also be why they are going everywhere.

I'm sure others may come along with more advice, however maybe try searching litter training in the search bar to the upper right hand side of the website and it should bring up lots of results

Rabbits are getting broody at this time of the year so I would imagine this is why your female is claiming areas. Most does, when spayed, become much cleaner as they are not governed by their hormones as much. Good luck with this.