Based on what safe mode does:
"Verifies your startup disk and attempts to repair directory issues, if needed"
"Loads only required kernel extensions"
"Prevents startup items and login items from opening automatically"
"Disables user-installed fonts "
"Deletes font caches, kernel cache, and other system cache files"
https://support.apple.com/en-gb/HT201262
This is a safe operation. Maybe try delete the cache files on the mac as it's possible there's a cache/directory issue:
1. Open the mac terminal.
2. Type cd ~/Library/Caches in the command line to navigate to the cache folder.
3. Delete all cache folders by entering rm -R * .
Let me know if that helps!