How old is Rupert? You should have your vet check for a urinary tract infection though, a change in potty habits ususally suggests a medical problem, UTI is often the problem. They will need a fresh catch of urine to test at the vets office.
If there is no infection, back to basics is a the right way to go. Shorten the amount of time between trips out to potty.
If there is no infection, back to basics is a the right way to go. Shorten the amount of time between trips out to potty.