How to recover lost local reminder lists in the Reminders app on iPhone?

Is there any way to restore local reminder lists? I went into my reminders app the other day and all of my local reminder lists were gone. I had not updated my phone and was unsure why they suddenly disappeared. I tried to restore them on the iCloud website but they were not iCloud synced lists so I couldn’t get them back that way. I also tried to use the search bar in the reminders app and see if any of my reminders appeared in the recently deleted section but they wouldn’t appear. I haven’t backed up my phone to my computer yet either so I don’t have a way to restore them from a backup file. I have a feeling that I will be unable to get them back and that they are permanently gone, which is very frustrating. If anyone has any ideas for getting them back or if anyone else has experienced this I would love to hear your input.

[Re-Titled by Moderator]

Original Title: How to restore local reminder lists in the reminders app - all local reminder lists suddenly disappeared