When editing, it is reflected in other images

Hi @＠キョロ! Thank you for reaching out, and welcome to the community! I'm sorry to hear about your issue. I understand it can be frustrating.

 

Here are a few things to try out:

 

1) Make sure Lightroom and your OS are up to date.

2) Reset your preferences: Quit Lightroom. Press and hold down the Option and Shift keys while opening Lightroom.

3) Turn off the GPU: Go to Lightroom > Preferences > Performance tab > Set "Use Graphics Processor" to Off > Restart Lightroom.

4) Clear Cache: Go to Lightroom > Preferences > Cache > Click on "Clear Cache"

5) A corrupted preview can indicate a problem with the synchronization process. Look for the cloud icon in the upper-right corner of the Lightroom interface. Or, check out this Helpx article to solve any sync issues: Photos stuck syncing in Lightroom

 

Let us know how it goes! 

Cheers!