piercing issues !!

hey guys, i got a few piercings in september. i got a third lobe piercing on both ears and a conch piercing on my left. everything healed perfectly but all of a sudden now the lobe piercing on my left year is sore and kind of warm. theres no discharge though. i had gold earrings in and switched them to a pair of titanium ones. i’ve been cleaning it with saline and putting tea tree oil for about a week now but no avail.

would like to know why this is happening and what i can do to make it better !

thanks in advance, hope everyone is staying safe :)