Hey there and welcome to Apple Support Communities sharath180,
We can certainly understand your concern and can help provide some insight.
We recommend checking out these steps for more information on how to record a video in slow motion and see if it matches up with your procedures.
" Record a slow-motion video
When you record a video in Slo-mo mode, your video records as normal and you see the slow-motion effect when you play it back. You can also edit your video so that the slow-motion action starts and stops at a specific time.
- Open Camera, then select Slo-mo mode.
On iPhone 11 models, iPhone 12 models, iPhone 13 models, and iPhone 14 models, you can tap
to record in Slo-mo mode with the front camera.
2. Tap the Record button or press either volume button to start recording.
You can tap the Shutter button to take a still photo while recording.
3. Tap the Record button or press either volume button to stop recording.
To set a portion of the video to play in slow motion and the rest at regular speed, tap the video thumbnail, then tap Edit. Slide the vertical bars below the frame viewer to define the section you want to play back in slow motion.
Depending on your model, you can change the slow motion frame rate and resolution. To change slow-motion recording settings, go to Settings
> Camera > Record Slo-mo.
Tip: Use quick toggles to adjust the video resolution and frame rate while you record. See Use quick toggles to change video resolution and frame rate. "
For additional information, check out this link: Record videos with your iPhone camera - Apple Support
These steps will help ensure your device is working with ease and can fix common issues like the ones you’re experiencing.
Kindest regards!