2016 Z3 pressure higher than expected followed by lower than expected.

[Tron]

I have a 2016 Z3, it went into limp mode for a pressure higher than expected fault. So I replaced fuel pressure regulator and it cleared the code and ran fine. I put it in the lake and about 10 minutes later it went back into limp mode and said on the screen that fuel pressure is lower than expected. Does anyone have any ideas for me?

Thanks