Years ago I had a neighbor who’s dog limped. The neighbor was quite worried and concerned. Nothing seemed wrong, but still the poor little doggie limped. How sad. Even lots of love and attention - the front left paw was not working
Until it did work. It seems the little puppy started to limp on the right paw instead of the left. She forgot which paw was hurting. Turns out she was faking just to get all that love and attention.
Actually, lameness in joints at different time periods can be an indicator of polyarthritis caused an autoimmune disorder. My dog has sterile nodular panniculitis which is an autoimmune disorder. On her last flareup, she would limp on one leg, then on the next day limp on the other. Treatment is steroids.