Empty screen when starting an nx session from another nx session on branch 3.6.x (2023/05/10)

[Djelff]

I first start the initial nx session, then several slaves to other servers. It's just more convenient that way.

Appearance on releases 3.5.99.25/26 Appearance on branch 3.6.x (2023/05/10)

Observations:

1. Running under xrdp session with the current branch has the same appearance as with releases 3.5.99.25/26
2. Replacing /usr/bin/nxagent from releases 3.5.99.25/26 restores the previous behavior.
3. Replacing the code of nxagent from these releases into the current branch and building does not help.

What other changes in nx-libs could affect this behavior? How can I help restore the old behavior?