"LONG" Query POST to Virtuoso ends with "wrong path" while GET trunks the the query

[lroffia]

Describe the bug
A clear and concise description of what the bug is.

To Reproduce
Steps to reproduce the behavior:

1. Go to '...'
2. Click on '....'
3. Scroll down to '....'
4. See error

Expected behavior
A clear and concise description of what you expected to happen.

System information(please complete the following information):

• OS: [e.g. iOS]
• Engine version [e.g. 22]
• SparqlEnpoint used [e.g. blazegraph 1.0.7]

Additional context
Add any other context about the problem here.