The blurriness could be because of a number of issues:
- Fingerprint smears on the camera array
- Moisture buildup in the camera cover
- A software update bug
IIRC the last update you got came with camera improvements. I would first recommend that you clear your camera's cache and data to see if this fixes the issue. If it does not, you might need to head over to a Samsung Service Center to see if this is a hardware issue.
You can book an appointment at a day convenient to you right through your Samsung Members app! Just tap Support > Book an appointment to find a Service Center and slot that works for you.
We are sorry to hear about your experience with the recent updates on your beloved Samsung Galaxy S21 Ultra having issues with a blurry front camera, and we apologize for the inconvenience it caused you.
I really understand what you are feeling right now, expecting your device to perform better after an update but came up short, then I will feel the same too. But don't worry, we are here to guide you, and offer solutions to restore your device to optimum performance.
If the issues remains, you may submit an error report through the Samsung Members app as follows:
Step 1. Long press Samsung Members icon on Apps screen and tap Error reports.
Step 2. Tap OK on agreement popup to send system log data.
Step 3. Select Symptom category "Camera".
Step 4. Describe the problem in details and SEND.
How to submit an error report on Samsung Members app? | Samsung PH
If the problem persists, immediately bring your device to the nearest Samsung Authorized Service Center. Rest assured that our Samsung engineers and tTechnicians are competent to assess your device with suggestions, and offer to provide prompt solutions to restore it up to optimum performance.
For more assistance and guidance, you may contact us via our online Samsung Customer Care support channels below.