[22F] Need advice handling my [24M] boyfriend’s friendship with a [24F]

I’m 22F, my boyfriend is 24M, and we have been together for 1 year. The girl he is friends with is 24F.
I’m looking for advice on how to handle a situation involving my boyfriend and one of his female friends.
She knows I’m his girlfriend. I followed her on Instagram because I wanted to know who she was, and she ended up blocking me on both Instagram and TikTok. I believe she blocked me after I changed my profile picture to one of me and my boyfriend.
She still messages my boyfriend, though. Recently, she texted him “hey.” He replied “hi, what’s up?” Since I knew she had messaged him, I told him to ask what she wanted. He then sent her, “Kayla’s wondering what you want lol.”
She replied, “Oh my bad I’ll let you go.”
He then asked her what was going on, and she replied, “Nothing bye.”
The part that bothers me the most is that my boyfriend had previously deleted messages between them. When I asked why, he said he deleted them because he didn’t want me to think anything bad. I told him that deleting them made me more suspicious, because I couldn’t know what had been said.
I told him not to delete or hide conversations from me, and he promised he wouldn’t do it again.
I’m now unsure how to handle the situation. I’m considering either leaving the girl alone and paying attention to my boyfriend’s actions, or contacting her directly about blocking me. I don’t want to create unnecessary drama, but I also don’t want to ignore something that could become a bigger issue.
I’m looking for advice on how to handle this situation, particularly whether it would be better to leave the girl alone and focus on my boyfriend’s behavior, or address the situation with her directly.