is it a bug or is it just me?

When I say that sometimes when I switch from, in my case, B to A preset, the midi characteristics transfer into the A preset, I need to explain the circumstances. The B preset is permanently occupied by the Ruckers harpsichord. I have a relatively complex set up for the Ruckers. I tweaked the various registers to sound well separately and together on my system, allocated spare notes at the ends of the keyboard to send midi signals to change registers, thus the lowest note brings in the lower 8', the next the lower 8' and 4', the highest the 2 8's etc. I do not change registration that often but there's those pesky French rondeaux which run on for pages and some distinction needs to be made between the refrain and the various couplets and there's no time to reach a far key. So, I left the una corda pedal to activate the buff stop and allocated the sustain pedal to the 2 8's and the sostenuto to the upper 8' for instant changes. I could, I think, have not done so far, create alternative versions to create different combinations e.g. lower 8' and 4' on the sustain pedal. So, when I switch to a piano on the A preset, depress the sustain pedal, I am greeted by the sound of the Ruckers 2 8's, which is a little disconcerting. I am aware of the facility/need to attach different midi settings to an individual instrument and have not carried out exhaustive tests, but I have re-instated different piano midi settings often enough to believe that it's not that which is causing it. In any case, even if the piano preset had not had a particular midi attached to it, the Ruckers, or any other preset, should not transfer its midi settings to another instrument.

Any thoughts from users and Modartt are welcome.