Files delete as files on laptop delete

I know this question must of been asked before but I can not find it.And I’ve been looking for hours. My iCloud storage is full on MacBook. And I want to save home photos/movies on the external drive, and create space on the computer. I tested it out and deleted 1 thing from computer and sure enough it was deleted on passport drive. Is there some solution that can be made. I thought maybe there could be a lock on the external drive to prevent it from deleting til ready? And am I missing something?
Thanks

How are you putting the files onto the MyPassport?

If you’re using WD Sync then that will keep the MP as a direct copy of the source folder/drive, including when you delete stuff. If you don’t want that then you want a proper back-up solution rather than a sync one (for example WD Smartware) or just manually copy stuff across and don’t sync at all.

No I am not using WD Synch. When I started I was just dropping files into the drive. The more I read the more I started to realize it is much better to keep stuff in multiple locations. So I did a backup with time machine. The files look to be the same place where I left them on My Passport. Although I’m wondering. After putting the folders with the home movie clips in a different place(like download) menu piped up saying after moving folders it will take it out of iCloud. Which it looked like iCloud wasn’t full anymore. Mainly I don’t want to lose those home movie clips. I’m new to all this and I hope by backing it up was the right thing to do ( particularly when clips are said not to be in iCloud anymore)

Backing up is certainly the right thing to do, as it using multiple places on seperate drives/devices for important stuff (see in this forum the number of people panicing when they’ve put everything on one external drive which has then failed).

I’m not a Mac user so I can’t comment on how Time Machine may handle files, but the confusion between Sync and Backup is another common topic here so I thought it worth mentioning it.

thanks for helping