We are sorry to hear about your frustration while in gaming experience with your beloved Samsung Galaxy A53 5G having issues with multi-touch. I feel and understand why you are worried for a device that you've take care so much. If my device is facing similar experience, I will be bothered too.
Before you try out the below recommendations as to your solution, be sure to check if your device's software are updated with the latest version. Please check how to update your mobile device's software in the following order.
Step 1. Go to Settings > Software update.
Step 2. Tap on Download and install.
Step 3. Follow the on-screen instructions.
Self-Diagnostic check on the Samsung Members app.
Step 1. Run Samsung Members and select Get help on the lower half of the screen.
Step 2. Tap View tests located under Diagnostics.
Step 3. If you would like to run through all of the Diagnostics checks, tap Test all.
Step 4. Your Galaxy phone will then run through the checks.
Step 5. Follow the on-screen instructions to complete the check.
Step 8. For individual diagnostic checks, you can view your results after the check is complete.
If that doesn't fix the problem, you may submit an error report through the Samsung Members app as follows:
Step 1. Launch the Samsung Members app, and then tap the Support icon for more options.
Step 2. Scroll and select Error reports.
Step 3. Choose a category of your concern. Select "Sensor/Touch".
Step 4. Choose the frequency of the issue you are experiencing. Enter issue details or attach a video or screenshot. Then press Send icons to complete the report.
If the issue persists, immediately bring your device to the nearest Authorized Samsung Service Center in your area. Rest assured that your device will undergo an assessment to pinpoint the root cause of the issue. Our Samsung engineers and technicians will guide you and offer solutions to restore it.
or book an appointment with the Samsung Members app as follows:
Support > Book an appointment to set one.
Should you need further assistance and guidance, you may contact us via our online Samsung Customer Care support channels below.