Not receiving any notifications in my Samsung S26 Ultra

Your screenshots already show Teams notifications enabled, Android notification categories allowed, and battery use set to Unrestricted. They also show that blocking notifications while active on other devices is off, so repeating those changes would not address the evidence. Confirm that the affected account and organization are selected in the mobile app, then arrange a test chat message and call while the phone is locked. Compare Wi-Fi with mobile data, and note whether messages appear immediately when you open Teams or remain missing there too. This separates an absent alert from a broader message-delivery problem without assuming a Samsung defect. Check for Teams and phone software updates, then record the app version, Android version, exact test times, and results. Microsoft's documented escalation is through Teams Settings, Help and feedback, Send feedback. Include the screenshots and observations rather than factory-resetting the phone before the failure is understood.