Waves Maserati level imbalance on mono>stereo application

just trying out the waves maserati plugins.
they provide mono>stereo and stereo versions.
i assumed that by sending a mono trk to a stereo grp in which i insert the mono>stereo plugin would be the correct application. but this causes a strange level jump on the L channel which becomes 6db louder than the right channel. when i bypass the plugin the effect of +6db stays on. only on disabling the plugin the normal balance expected from a mono source on a stereo grp returns. when using the stereo version of the plugin in the insert things are all right.
i am just curious if anyone has an explanation for this. what purpose has the mono>stereo version then anyway?

setup:
mono trk routing to stereo grp
stereo grp insert: maserati mono>stereo plugin
result=Lch+6db
plugin bypass= still Lch+6db
plugin off= Lch=Rch level
stereo grp insert: maserati stereo plugin= everything fine

Generally don’t use the Mono>Stereo plugin set, they are for daws that use a different procedure.

If you inset one on a Cubase Mono channel then you wont get the benefit of the stereo output as it’s inserted in a single (mono) signal flow (the output of the channel only becomes two channels post panner), If you insert one on a Stereo channel, you wont get the benefit of a Stereo input as the plugin only has one input lane (generally sourced from the left side).

So for the Stereo plugin set with a mono channel, either make a stereo channel and drag the mono parts onto that, or use a stereo group channel and insert the plugin on that.

i tried both variations with the same results as i described (Lch+6db)
anyway, it is clear now that the mono>stereo are of no use in any configuration.

thanks

Thats what I said first?

“If you inset one on a Cubase Mono channel then you wont get the benefit of the stereo output as it’s inserted in a single (mono) signal flow (the output of the channel only becomes two channels post panner), If you insert one on a Stereo channel, you wont get the benefit of a Stereo input as the plugin only has one input lane (generally sourced from the left side).”

yes, you did.
thanks again