Thanks for reaching out, sorry for the trouble with Lightroom on your phone. We are here to help!
Could you please share the exact iOS version on your phone? Have you tried any troubleshooting steps like removing and reinstalling Lightroom? Do you use Lightroom desktop or Lightroom Classic on any other machine?
Please disable Wi-Fi or mobile network internet on your phone when you open Lightroom to halt any photos from syncing.
Please check here for the steps to disable auto import from settings within Lightroom.
Please let us know if this helps.