@jellycat1 - My DD had a similar problem, but that was a very long time ago, so advice could very well be different now.
My HV pointed out that there's a heck of a lot that needs to go on for a toddler to coordinate what's needed for walking. Back then, DD couldn't go into "proper" shoes because reputable shoe shops wouldn't do that if toddlers couldn't demonstrate a standard walking gait independently. But the HV recommended proper shoes for a couple of reasons:
Standard shoes impede tip-toe walking, because the rigid soles don't bend enough. The problem with that is that DD kept tripping over, so I had to hold her hand until she learned to rotate her ankle upwards enough to do the heel-toe gait.
The heel-toe gait requires enough stretch in the calf muscles/tendons to enable sufficient ankle rotation. Many women who habitually wear high heels find it difficult to go back to flats, because their calf muscles/tendons have become shortened.
Then there's proprioception, where you know where your various limbs are and what they're doing. Goodness knows how toddlers figure all that out - parachutists and astronauts have to go on special courses.
DD did eventually get her act together. I can't remember how long that took, but probably a matter of a few weeks. Of course, the shoes might not actually have made any difference at all - just DD catching up with herself.
I'd recommend just going with the flow, and supportive footwear, for the next couple of weeks or so. If the problem doesn't then resolve, ask your GP for a paediatric physio referral. If one-sided tip-toe walking goes on too long, I would think that can throw out the muscles/tendons higher up in the hip and spine and so on. Good HCPs involved with young children would prefer to catch a problem earlier rather than later.