As I've said, several times already, we can't fix anything in the F-18, unless Microsoft decides to release an update.
The only thing that we can do with regard to possible issues, is to find workarounds, for example, in case of the crash with the SEQ button, we found it only happens if a flight is loaded and it contained an active flight plan when it was saved. The workaround, in this case, is to always save flights without a flight plan active, and always load a flight plan separately.
With regard to the NAV frequency selection as I've said, several times already, this is NOT consistent. I wasn't able to reproduce it initially, then it happened a couple of times, then it disappeared again. It maybe depends on a FSX setting, maybe international settings or something like that.