7 year old Beardie who persistently digs up carpet during night. To the point She has ripped up carpet
She has done this for several years also chewed furniture but that's pretty much stopped now.Doesn't dig so much during the day

As far as can be discovered by vet she has no pain. Had joint supplement and digestive supplement raw fed since puppy.
Tried adjusting meals no difference.
She has a misplaced anal gland which has to be emptied manually every 6 weeks of so. Very difficult to empty. No difference in digging around anal gland

She wakes her owner up with her digging. She can be quite frantic at times and difficult to stop.

Any ideas as to cause or cure

Some dogs seem to be more diggers than others None of my current (sadly my much reduced) pack have dug up garden/flooring etc. But many years ago I had a Goldie who dug holes in the kitchen floor. My BC Meggie used to dig a hole in a part of the wall in the hall. We gave up repairing both !

Does she sleep by her owner or separately? Just wondering if could be some form of separation anxiety

In the same room as owner and other dog. Usually settled in early hours then sleeps like a log

One of our dogs repetitively digs up mats, tiles and laminate flooring. He also has seizures. The neurologist says that this kind of repetitive behaviour indicates damage to his frontal lobes. Not saying that's the case for the Beardie, but just a thought. And no, we haven't managed to train him out of it yet. Every time we think we're making some progress he has another fit and we're back to square one.  Heigh ho

As digging is commonly connected to pain, I would ask for a long trial of pain meds - 4-6 weeks at least.  Very VERY often vets will miss pain simply because dogs hide it really well, or manipulation of joints doesn't trigger it.

My girl digs at night. At First she would be frantic with it I got her a night light as her eyes had started to cloud a bit and I had noticed her night vision wasn't as good. It helped for a while then she started again and we noticed she was also having trouble jumping up on the furniture. Turned out she had osteoarthritis so started her on lebrella and that's and that's working for her.
Now she only digs at night when she wants something (as she knows it gets my attention) like she's hungry, she does actually need the loo even though she had the chance, she wants to sleep in my mum's room not mine, or her son or me is laying in her spot. I now make her go out to the loo twice right before we go to bed and give her some food at midnight when I go to bed. The digging now isn't frantic, she will dig a couple then stop and look at me and if I'm ignoring her repeat. She has a metal food bowl in my room that she will start chucking about it diging the rug doesn't get my attention.