Call waiting
today, my husband called me at 7.00 clock on whatsapp and we had a short conversation. Then I disconnect the phone. After like an hour he tried to call me ..it says call waiting or the person you are trying to reach is on another call while at the same time I tried to call him back it says you can't place a call while you are on another call. Genuinely speaking, I was not on any other call. I have no idea why this happened . Besides, I have many recents app opened is that could be the issue? Then I removed all the apps then called him again and It worked.
but my husband is asking me why you were on another call and I am saying that I wasn't on another call. How can I prove him or why it happens?
iPhone 12 Pro Max, iOS 14