Any functions to remove background noise not working in Audition 2021 (i.e. De-noise, etc.)

Hello! I just updated my Audition and I am trying removing some air conditioner noise (basically ambient noise) from a recording. Usually I use the de-noise effect and it removes or at least dampens the noise to an acceptable level. This time, no matter what processing focus I choose or what amount of noise reduction I set it to, it absolutely does not change the recording's sound AT ALL. I have also tried using FFT filter, going into the spectral view & removing select frequencies...none of these produce audio that sounds good or will work. Prior to updating, I have never had this problem before. I tried running the de-noise function in Audition 2021 installed on another computer & it worked perfectly the way I expected--it removed the air conditioning noise completely. I tried deleting and re-installing Audition and it still did not work. Help!