Yup, can confirm this is indeed a bug, I noticed the fuel flow meter starting to go haywire after mach 1.4+. Here's the track at 37,000 feet, 100% fuel clean with no fuel tanks and 4 AIM-120C under CFT.
F-15E fuel flow bug above mach 1.4.trk
Edit* This mach 1.42+ fuel flow bug also occurs even with fuels tanks attached on the wings while still having fuel in them. Here's the track file below.
F-15E fuel flow bug above mach 1.4, with EXT fuel tanks not empty.trk