I have the same issue as the posters above.
I used the
Latest International FW shared in this post and my
screen is upside down and mirrored. The flip settings in the system preferences does not work anymore. If it helps, the projector was just bought recently so I don't know if the newer batches of the same projector has a different internal setting inside that flips and mirrors the image when incompatible (older) firmware is installed.
If anyone knows how to fix this issue please share it here. I just created an account to let everyone know.