Thank you, juujika, for letting us know your experience while using your Samsung Galaxy device having bugs and unresponsive screen, multi-ghost touch issues.
Really understand what you are feeling right now, and expect your device to perform at its optimum.
But don't you worry, we are here to help, guide, quick fixes and offer solutions to your device's problems.
A) Ensure that your device is up-to-date with the latest Software updates.
Settings > About Phone > Software Updates > Download and Install > Follow On-screen Notifications.
Also, check Samsung members apps, notification bell icon for any updates information available for your device.
B) Running the Diagnostic Tools under 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. Diagnostics checks, Individually Tap the following;
"Touch screen"
Step 4. Your Galaxy phone will then run through the checks.
Step 5. Follow the on-screen instructions to complete the check.
Step 6. You can view your results after each check is complete.
C) 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 detail and SEND.
D) Clear Cache Partition.
Step 1. Turn-off your phone. Step 2. Plug in the USB cable via PC or Type-C earphones (in case its USB-C to USB-C). Step 3. Then press and hold Power and Volume up buttons. Step 4. Release the power button. When the recovery screen shows up, release the volume up button. Step 5. Navigate to and select Wipe cache partition (Volume up and down is for highlighting options and power is to select). Step 6. Navigate to and select Yes. Step 7. Press the power button to select Reboot system now. Then, check your device by connecting to Wi-Fi.
E) For more assistance, you may contact us on our online Samsung support channels below.
