How bad is it with a loose connection once charged iPhone 15, Android charging cable?

Forgot my original charging cable and used my girlfriend's charging cable (Samsung adapter and USB-C cable) this morning

After 1 hour, I noticed that every 2-3 seconds the charging symbol in the top right corner switches back and forth between "charging" and "not charging", almost as if only pulses of electricity were being received, so the charging flash symbol always disappeared for a short time… like a loose connection and it may have been one because I only noticed it while using it

How damaging was this one hour of loose connection to my battery? Or is it harmless for the battery?

I'm worried because my iPhone 15 is relatively new (half a year, not even) and I'm trying to do everything right for a long lifespan… I can't judge that at all because I don't know much about electricity and batteries