It might be separation anxiety or just a nervous energy that dominates their personality but either can lead to your dog acting out or possessing unwanted obsessive behaviours.
Most anxious dogs will benefit greatly from distraction, and this is where toys are super helpful as they give them something to do while also delivering a sense of purpose. Some obsessive behaviours will benefit from toys also, but if problems persist, please see your nearest dog trainer or behavioural expert.
One of the biggest benefits toys can deliver to help with anxiety is consistency. Depending on which state of Australia you reside in, Covid-19 has made our lives very non consistent, especially in states that have been in and out of lockdown. When our schedules are all over the place having a favourite toy by their side all the time will help create some stability for them.
When giving a new toy to your dog, be sure to supervise them in the initial stages to make sure everything is safe and good. Once everything is good you can try hiding multiple toys around the house before leaving to keep them interested while you are gone.
Other great ideas for generally anxious dogs are increasing the amount of exercise. Let less energy you pup has left the less nervous energy they will have also. Also try Aromatherapy, you can use a calming blend and spray on their collar or their soft toy to help their anxiety. Music has also been known to be a great tool for comforting anxious pets.
You will be able to see if any of these solutions work early in your dog's appearance, as they should start to look less apprehensive and less “stiff”, you will also see it in their behaviour as well, things like less barking and pacing as well as a reduction in the destructive behaviours like chewing and digging.