XClick always misses with a horizontal offset

This is exactly what I meant, that Xclick is making browsers animations less reliable. I had the same issue where my browser was set to 100% and it still would not hit the target. It took me a week to find out what was going on and I hope that issue applies to you to:
Make sure the kantu browser where you have all your scripts stored is also set to 100%. I must have had it changed by accident and did not even know it had anything like a zoom setting.