I think i found a way to prevent your phone from automatically filling up your gallery with stories.

[Teodor]

Here is what I did to prevent my Galaxy A34 from filling up my gallery with stories:

1. I opened the Gallery settings

2. I disabled customization service

3. I opened the phone settings and navigated to apps

4. In the apps settings I navigated to the Gallery Stories app and I pressed on Disable

[realaud]

I've never gotten automatically created gallery stories. Never enabled or disabled it. And I have customization on. From my settings, looks like I have to manually create stories.