ADL5513 log amp undershoot

ADL5513 pulse response

I am using this device at 2.4 GHz driven with a balanced feed from a Minicircuits balun, to avoid log amp tails.

However, i see an annoying undershoot at the end of the pulse. The output of the log amp is buffered with an AD8051 and the undershoot appears at all power levels, with or without 22pF CLPF cap. Running off 5Vdc. Test source is an R&S SML03 sig gen, 400ns pulses between -60 and 0 dBm. Undershoot is present at the input of the video buffer amp.

The problem with the undershoot is that it eats into the rising edge of a second pulse that comes after the first.

Any ideas or is it to be expected?