fast mode vs. slow mode option

[ramalama]

Every time I convert, I select slow mode to convert from flac or ape to MP3 VBR V0. This setting is sticky, so I am selecting it without changing a thing, if that makes sense. However, when the files are compressed and I view their properties with the program it always says fast. How can I force it to use slow?
Using 13.1.0.2

Thanks! This has happened many times, so I know it is not me doing it.:(