Hi @judynguyen ,
Just verifying that there isn’t a screen protector covering the screen as sometimes these can interfere with the correct operation of the touchscreen but more so with the fingerprint sensor which is located in the screen itself.
Try starting the phone in [https://www.hardreset.info/devices/huawei/huawei-p30-pro/safe-mode/|safe mode] just in case it is a downloaded app that may be causing the problems.
If still no good try [https://www.hardreset.info/devices/huawei/huawei-p30-pro/wipe-cache/|wiping the cache partition] just in case it is corrupted cache data that is the cause of the problem
If it still fails then just because there are no visible cracks on the screen doesn’t mean that there hasn’t been any damage to the delicate internal connections in the display assembly itself.
As a DIY repair all you can do is to open the phone and check that the display assembly flex cable connection to the motherboard is secure and if it is, then to temporarily replace the display assembly to determine whether the problem is in the display or the systemboard.
Here’s the ifixit [guide|129875] guide which should help you to do this.
Replacement display assemblies are available online. Just search for ''Huawei P30 Pro display assembly'' to get results for suppliers that suit you.
If doing this yourself seems too daunting, contact a reputable, professional mobile phone repair service and ask for a quote to repair the phone.