Additional features, settings, or issues not covered by specific Microsoft Teams Free categories
This has been happening to me for a while as well. I'm 98% sure it all started around iOS 17 and a Teams update.
I noticed I was only getting notifications during certain times of the day. I believe Kyle Ryan is correct. When I'm away from my company laptops, I seem to be getting the notifications. The option to Block notifications "when active on other devices" was the cause. The switch was enabled on all my devices which explains why I was sporadically getting notifications.
To disabled it, go into the Teams app, tap your profile icon in the upper left and tap Notifications. You'll see the option towards the bottom.
Thanks Kyle.
FYI: If you're still having an issue, double check the iOS Focus settings. If you have a Focus feature enabled (Personal, Work, Driving, Sleep etc..) and Teams isn't in the allowed apps, it will also mute the notifications. Basically like a tailored version of do not disturb.