Thanks for reaching out to us here, to inquire on what to do about Your Samsung Galaxy A71 having issues with flickering and changing yellow tones after an update.
You may Submit report error through Samsung Members app.
Step 1. Long press Samsung Members icon on Apps screen and Tap Error reports.
Step 2.Tap OK on agreement popup for sending system log data.
Step 3. Select Symptom category. Tap "Display".
Step 4. Describe problem in details and SEND.
For more assistance, you may contact us on our online Samsung support channels below.
Hope this content is helpful and your device's display issue gets solved.
Make sure to click the ACCEPT AS SOLUTION button in your subsequent response, if we have satisfied your inquiry.