Tried factory default many times and you will have to trust me that the lens is perfect no marks or fingerprints.
I'll take my spare 225u-hni and SD29204T-GN home tonight to see if I can replicate the issue you are having.
I've had blur issues in the past with other cameras and wasted a lot of time chasing my tail.
In those instances, the issue was the encoding stream, lowering the fps to 10-15, cranking the bit rate to max, switching to CBR and changing the exposure to increase shutter speed (side affect is decreased light levels) helped a lot. (compensated by cranking up the brightness and in the end adding extra lighting).
But that location was very dark.
One issue was a fault with the sensor, was partly blind and had issues offloading data. (warranty replacement fixed the issue.)
Another was smudge marks on the inner lens sections which was easily fixed by pulling it apart and cleaning it. (Both were Cisco Meraki Cameras ironically)
Another thought is the light colour vs surroundings.
Some cameras have a hell of a time processing certain light kelvins, such as the 2500-3500k used in older street lighting especially when there is brown/orange or white houses/walls/objects around.
One test would be to take one of your other Dahua Star Lights, configure it to the same encoding, zoom level and image settings as your PTZ, then by hand follow a moving target such as a person, does it also blur?
If it blurs as well, then you know it's a setting issue but if it doesn't, then you know there might be an issue with the PTZ.
Another thought is to turn off all the WDR image processing, crank the ISO to max and flatten the contrast, make the image dark/ugly as hell but that would also be another test.
I'm sure
@EMPIRETECANDY will do a warranty replacement if you have gone through all those steps.