Notes jump up a whole step after playing

Everything was great - and then - all of a sudden - notes played on virtual instruments would jump up a whole step at various times.
Anybody else experience this phenomenon?
playing on Windows 10

were there any physical changes to the guitar? strings, intonation?

is legato on/off?

can you get it to happen with an internal mg2 synth and the virtual instrument at the same time? (ie: internal synth stays on pitch while virtual changes)

is anything which might transmit pitchbend attached to the system?

these are all just wild guesses, i haven’t experienced this issue.

I unplugged all the other usb devices from my computer and the problem disappeared. Thank you very much for replying!!!