Hi Zahir,
I wasn't quite clear on what part it was you were talking about having replaced; my best guess is you're talking about the charging cable; if that's the case it wouldn't have anything to do with the touch screen issues you're having.
For that matter, neither would the charging port, so you can lay that to rest. This is almost certainly an issue with the digitizer itself or possibly the flex cable connecting it to the motherboard. Generally this sort of failure comes about as a result of some kind of damage, whether that's being bumped, dropped or exposed to liquid; it often doesn't take much to mess up the delicate connections between the electronic circuits etched into the glass and the flex cable that carries those signals to the motherboard and can happen even without any visible cracks in the glass.
On some tablets it's possible to replace the LCD and the digitizer separately, but I see nothing to indicate that's possible on your iPad so my conclusion is you most likely are going to have to replace the entire screen assembly.
There's really only one thing you can check and to be honest the chances you're going to be able to fix the problem this way are microscopic, but outside of just going ahead and ordering a new screen, it's about the only test you can do. I'm suggesting you open up the iPad, which involves carefully removing the screen, and checking the display connectors. There are four of them; one is for the digitizer and one or more other is the LCD, and finally there's a LIDAR sensor assembly as well, but unfortunately the guide doesn't distinguish between them so you'll just have to check them all.
So what you'll want to do is pull up the screen replacement guide here.
iPad Pro 11" 1st Gen Screen Replacement - iFixit Repair Guide
Follow it through Step 32. After that you'll want to go over all four connectors both on the flex cables and on the motherboard with a magnifying glass and a bright light looking for bent or broken pins. Bent pins can sometimes be straightened with fine tip tweezers, but of course broken pins are problematic.
Assuming the connectors are all okay, go over the flex cables and check for any damage there; excessive bends can break the copper connection in them so check any folds carefully.
Once you're satisfied there's no physical damage to be seen, use some 90% or higher concentration isopropyl (rubbing) alcohol and clean all eight connectors. Give them a minute to dry then carefully plug everything back together, reconnect the battery and power it up. See if it's any better; if that does the job button it back up and congratulate yourself on a successful repair.
If however, as I suspect, nothing changes, then the only thing left to do is to replace the digitizer, and since you can't replace just the digitizer you'll need to swap out the complete display assembly. Of course you can support iFixit's repair efforts by purchasing your replacement screen right here.
iPad Pro 11" (2018) A1980/A1934 Screen: Replacement Part
If you need to be cost conscious or have availability issues, you should also be able to easily find replacement parts on the major sites like Amazon, eBay or AliExpress and others.
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