Learn English idioms: something “rings a bell”
I don’t know if this is from American or British English, but it’s certainly used a lot in the UK. If something “rings a bell”, it means that you can slightly remember something but not exactly what.
“Can you remember that?”
“No, but it’s ringing a bell.”
“I can’t remember exactly, but that rings a bell.”
“There’s a bell ringing somewhere. Give me a minute and I might be able to remember.”