Maybe it looks different and you perceive it the wrong way but we were trying to help and support you.
However this appears to be difficult because understanding of what you have on you side, what is configured, working and not working is fuzzy. Is it due to cultural or language barrier, I don't know but, as a result, this is an heavy and painful task, reasons why I preferred to give up.
At least with this last post you make a clear statement that looks almost a conclusion: your point is that default gateway is missing on Zentyal box and you had to add it manually.
Trust me, and this is perhaps not your fault, it was not clear before or mixed in the middle of plenty of useless information. As network expert, what is, according to you, the added value of tracing route if you know that default route is missing? We are just all wasting time
You because you make useless tests, us because we investigate for something you already solved, at least with workaround.
So, as you now have the answer to your question, if you feel this to be a bug, open a ticket
and stamp this post as [SOLVED].
TTFN.