I had registered with lightroom and purchased a set of presets about a few years back. Bought a new I phone in the past month and redownoaded Lightroom app on my new phone, signed in to the same account. However, the purchased preset is no longer there and when I click restore purchases it said I do not have any purchases. However the presets are still on the app under the same account in my old phone.
When using the free version of Lightroom, presets and images are not backed up to Lightroom's cloud storage. Restore Purchase will not help, as that is only meant to troubleshoot Lightroom subscriptions and not purchases made via 3rd parties.
You will need to re-import the presets on your new device. Another option is to make a backup of your old device, and restore that backup onto you new device, if that's possible/desirable.