Exported song plays at lower pitch

Our original songs are in A
When we export a mix it is in F#, so lower pitch
We suspected a 48Hz/441Hz problem but we have verified that the song and all parameters are in 44.1 and it is like that
It happened suddenly, before yesterday, everything was OK
Thanks for the help

I found what happened. As suspected it was a 44.1/48 kHz problem but hard to detect. It was not in Cubase, it was in Windows Sound Settings of the Audio Output devices,. The MOTU was set on 48kHZ, which of course lowered the pitch of the song… That means that Cubase was playing in the right pitch, but all the other WIndows applications like VLC, YouTube, WIndows Media Player wrere playing lower pitch, I reset it on 44.1kHz and everything is OK