Forward recovery time of a diode
You did not stated what is the part number of the diode you use. Without much details of your intended application it is difficult to discuss about maximum frequency. But let’s presume it is STTH60L06C ultrafast high voltage rectifier (600 V, 6A).

The data sheet says:

trr (IF = 0.5A Irr = 0.25A IR =1A) 65 ns max.

tfr (IF = 30A dIF/dt = 100 A/μs VFR = 1.1 x VFmax) 500 ns max.

As you can see current IF for reverse recovery measurement (0.5A) is much lower than current IF for forward recovery measurement (30A), expectedly the duration is much lower in the first case.
In general, fast rectifiers have improved (minimized) reverse recovery time at expense of increased forward recovery time (and forward drop), compared with general purpose rectifiers.