Welcome! Your bunny’s behavior and reaction to what you did with her makes perfect sense to me. The reason she was probably doing so good at first was because she was too scared to venture out of the closet at first and found the litterbox a safe haven to huddle in while she was still scared, having been in her cage only a couple of hours and not yet having gotten used to that when suddenly she found herself in yet another new environment- your big room. Scared of all that open space where she fears she’s exposed to predators, she sought the comparative seclusion the closet offered and its even more appealing litterbox inside, an even smaller space that’s partially protected with its walls on all four sides in which she can feel partially hidden while she’s scared and stil taking time to see if there’s the threat lurking about of any attackers. After an hour, she was apparently over her fear enough to explore and since you didn’t seem to pose a threat, she was curious about you, came over to check you out and evidently even permitted you to pet her and maybe felt a little skittish from being touched so soon before she’d fully gotten used to you so she decided to take advantage of the open space to run like crazy like rabbits will sooner or later if they have open space. Since she hadn’t yet learned to use the litterbox yet as her exclusive toilet – the litterbox just seemed the most appealing place to hide in while she was scared and so she peed and pooped there when she had the urge as well while she was afraid to move and this was the only spot she felt secure enough in to claim as her own – she went wild and ran around, as a moving target is harder for predators to catch than a slow or stationary one, and she now regarded the whole open space as her toilet. The nice soft bed is an especially appealing place to a rabbit to pee and the whole place is up for grabs for pooping as well. They’re both a way of marking their territory to other rabbits, and yes, femaies are juist as territorial as mailes so mark just as much if not more.
I’d confine her to the closet using say, NIC grids to fence it off from the room, while reinforcing her to use her litterbox as a toilet by wiping up accidents outside the box and putting the wet pieces of paper towel in the litterbox along with her poops until she catches on and learns to use only the litterbox as her toilet however long it takes. Only when you feel confident that she’s stopped soiling outside the litterbox, give her just a little space in the room by extending the space with more grids, from the closet to include a small area outside the closet, while continuing to reinforce her litterbox habits until she has no accidents outside the increased space. Then take the next step and expand the size of the space by opening up the fenced in area and using more grids to enlarge it, still reinforcing the litterbox habits. You can continue taking slow gradual steps for however long it takes to reinforce the litterbox training, then increasing her access, until you give her the whole room. She’s likely to learn to adjust to being given access to more and more freedom, in steps, while still adhering to only using her litterbox as a toilet. Make sure you’ve bunny proofed the entire room first by either making sure all electric cords are out of her reach or enclosed in something chew-resistant (enclosing them in sump pump hose cut to size is probably one of the best. Most other cord protectors are not as chew-resistant so give the bunny plenty of safe chew toys to keep them busy which is good for them and you’ll want to do anyway. Also most houseplants are toxic so you’ll want to make sure those are also out of reach. Please post pictures!
.
