Large Pet setting is still too sensitive; cannot arm for away if the dog is home

I live in a small-ish two bedroom house and have a giant breed dog (English Mastiff). She constantly sets off the motion detection when the alarm is armed for away. It's set at the lowest setting (multi pet/large animal). When home alone, she's confined to the kitchen area. Ring's "solution" is to block off the area or lock the dog away from the motion detector. I have the motion detector near the backdoor - because that's where it's needed most - and cannot put a barrier up to keep her away from that area. Essentially, the alarm is useless at this point; I can either not use the detector at all or not arm fully when I leave. Has anyone else run into this issue? What solution did you find?