Ultra sensitive PSA vs PSA

Currently 50yr old, prostatectomy in 01/2022 @ 47yrs old.

For the past 30 months my uPSA has been <0.014. Over the past year I’ve seen my primary care physician three times for annual physicals and pre-hire bloodwork and she always measures my PSA. The results between uPSA taken by my urologist and PSA taken by my PCP are different. See results below:

Sept 2023 - PSA (quest) = 0.05
Oct 2023 - uPSA = <0.014

Apr 2024 - PSA (quest) = 0.04
May 2024 - uPSA = <0.014

Sep 2024 - PSA (quest) = 0.06
Oct 2024 - uPSA = please god <0.014!

I’m high anxiety and worried that the increase from 0.04 to 0.06 will also show an increase in my uPSA. More for this forum is how can tests be so different especially if the quest diagnostics test claims to be a 3rd gen with an assay lower limit of 0.02? Would love your comments and feedback or general knowledge on uPSA vs PSA testing.