VEGAS Pro 19 Update 5 (Build 643)

Hi, I mainly use VegasPro 19 to edit a radiovision program, but since I installed the new release 636 when I render for example only the Mp3 or Wav audio file it seems to work, but then once finished at some point the music freezes with a continuous annoying noise. This is a big problem because having to supply the files to 6 radio stations I had to fall back on other software. Support ... please solve it. Hello and thanks