layers disappear on the routed channel on PLAY MIX command

[AndrewFields08]

Observed Behavior

routing a channel on another one if run play mix on the first, on the second the other layers disappear and reappear.
using WIPE, PUSH or SLIDE the problem does not occur.

Expected behaviour

complete channel routing without the disappearance of the other layers

Steps to reproduce

caspar.txt

1. Start CasparCG
2. PLAY 2-10 route://1
3. PLAY 1-20 IMAGE
4. PLAY 1-10 VIDEO LOOP MIX 50
5. PLAY 1-10 VIDEO LOOP MIX 50

Environment

Commit: 5e29af9
Server version: 2.4.1
Operating system: Windows 10

[Julusian]

I think this is very similar to, perhaps a duplicate of #1307

There are 'known' issues with how the transforms combine when combined with routes, that make it a little broken