Dog weeing in DC room

[runsmidgeOMG]

Gahhhh again !!
So my female 5 yr old seems to like to wee in DC (3) bedroom. We have a downstairs stair gate that we have to close without fail otherwise she'll go up there and wee.
I read somewhere it's actually a subservient thing and that sometimes dogs urinate on their owners things to protect them or some such?! She never did this before DC arrived

Regular access to walks and outdoor space, eating well, cuddly etc.
Why do you think she is doing this ?
Wasn't her mattress this time thankfully but muttering grumpily as I'm throwing her play mat/rug in the machine again !

Can understand how annoying this would be. Could you mix some lemon and water and give the floor a spray? It's meant to repel the dog but I've never tried it

Is it because she's never allowed in that room?

I've read about dogs who aren't allowed in bedrooms (for example) and so whenever they manage to get up there, they pee. Could you maybe spend some time with the dog in there so she knows not to pee there?

Not subservient.

Dogs often go and find a place to wee where they will not be disturbed. This can happen if the dog is not totally house trained or maybe stressed.

If you are sure there is no urine infection etc and the dog has been vet checked, then I would go back to basics and take out to wee regularly and praise and prevent access to the bedroom.