Ok. Thanks for clarifying.
If your Guest network has Meraki DHCP (NAT mode) , then the Access Point will offer 10.x.y.z IP to wifi clients.
If you have a large number of clients in and out everyday, you may have duplicated IP every now and then.
In addition, sometimes a user might add the leased IP statically to his/her device.
If you found this post helpful, please give it kudos. If my answer solved your problem, click "accept as solution" so that others can benefit from it.