is this urgent?

https://imgur.com/a/sBEkBxM

Had my regular cleaning/exam in March with my long time dentist who didn’t mention any issues with my teeth. But while on vacation I had to see a different dentist when a crown came off. She mentioned this cavity on tooth #14 and made it seem pretty urgent that I get this treated soon and alluded to it being possibly more than just a filling. Confused since my regular dentist hasn’t mentioned it at all. No pain or sensitivity. The gum around it was a little irritated for a few days but is better now - I think something got stuck in it? I have good oral hygiene with brushing and flossing twice a day.