EFIS NAV CRS

I did a flight last night and the EFIS CRS marker would not slave to the GPS NAV CRS. I had to keep changing it manually?

Anyone experience this.? It was working (I think at one point)...... If so the only change made to the file was the addition of Nicks wonderful performance mods and Berts mandatory A/P mods....Could that be related? I would not think so?

Thanks.

Using the default GPS BTW..