Mixer fill, Mixer clip and route on CasparCG 2.3

The behavior changed between CasparCG 2.0.7 and CasparCG 2.3.
In CasparCG 2.3 Mixer clip command disappears after routinf the channel.
To reproduce this issue :

play 1-1 amb loop
play 2-100 route://1
mixer 1-1 clip 0.5 0 1 1
MIXER 2-100 FILL 0.5 0.5 0.5 0.5 1

First, the result with CasparCG 2.0.7:


The, the result with CasparCG 2.3 (clip desappeared on second channel):

Is there a way to keep clip in this case ?
Thank you for your help.