That camera is to old to get updated firmware. Mine is the 59225U-HNI, and I don't remember if I get any PTZ firmware updates in almost two years.
That camera, if I remember correctly, somewhere has a place where you can check the auto tracking, you could try that.
I found here this firmware: NEW SD59225U-HNI Latest New Firmware SD-Eos_MultiLang_PN_Stream3_V2.812.0000007.0.R.210706
...and from what i see it support SD50225U-HNI. I have also some problems with nightvision....is color mode set but if a car passes with the headlights on, camera become very darkness and remain in dark. i have to play with all settings to find best way.