GoldWave/LAME interface - Sound Level

I have been using Goldwave software (which uses the LAME encoder) for years to process MP3 files

Recently, I upgraded to v5.52 of Goldwave and started to notice unexpected differences in sound levels between input and output files, typically the output average appears to be -0.40dB lower

I switched back to Goldwave v5.25 and the differences disappeared

I contacted the Goldwave developer and he confirmed that "one of the differences between v5.52 and v5.25 is the MP3 encoder settings and the LAME encoder version" - he advised that "the latest version of the LAME encoder affects the average more than the older version, which is not unusual since the encoding process discards part of the audio to get better compression"

I was informed that "this does not occur for Wave files", but I was offered no solution to my problem with MP3 files

I wondered, therefore, if there was a method of retaining the original sound level on Goldwave v5.52 by adjusting a relevant LAME setting

Regards

Keith