@Alanlees1971: To be clear, are you finding that your Camera app is unexpectedly taking pictures while you're not using it? Where are you seeing the 'Recent' folder you mentioned e.g. Gallery app, My Files?
In the meantime, you may wish to try heading to Settings > Battery and device care > Battery > Background usage limits > Sleeping apps > Tap the '+ in the top right > Camera > Add, to see if this helps. Due to the unexpected nature of your query you may also wish to restart your phone in Safe Mode, as this will disable all third party apps, and help to determine if the problem is stemming from an external source.
To enter Safe Mode, press and hold the Power button until the 'Power off' prompt appears on the screen then release > Touch and hold Power off until the 'Safe mode' prompt appears then release > To confirm, tap Safe mode.
Monitor the performance of your device for a few hours, depending on the frequency of the issue. If you notice an improvement then please restart the phone as you would normally and uninstall any recently added apps (those introduced around the time you first encountered the problem).