(this is not exactly what I referred you to does…)
because Andrew, one of the FreePBX developers clearly said this:
The database was in ISO-8859-1 / Latin1 before which did support some other languages besides English either completely, partially or not at all…
As I said what I am suggesting you could do is unsupported and has caveats, one of them is that your national characters, if present, have already been corrupted and you must correct those entry after running those commands.
You should also make a backup before doing this (if you choose to do it)…