Civil is an entirely different matter.
This is regarding the right to a jury trial in CRIMINAL matters.
Regarding civil matters, the USSC has held that the 7th Amendment Constitutional Right to a Jury trial in FEDERAL court does apply to any civil matter brought under common law (mostly diversity cases), or in matters similar to common law where only a judicial remedy is possible (most recently there was a civil SEC case that was found to be enough like a common law case that a jury was ruled to be required).
That said, cases brought in federal court under admiralty and maritime jurisdiction generally do NOT have a right to a jury. They are traditionally bench trials, as they are considered matters outside of common law. The federal Judge sitting in admiralty jurisdiction will decide those.
Importantly…
There is NO FEDERAL Constitutional right to a jury trial in civil cases brought in STATE courts, HOWEVER, MOST states have state constitutional provisions of their own creating such a state constitutional right to a jury trial in various civil matters.
Regarding 6 vs.12 in civil, it all depends. Divorce cases in Texas that go to trial (most don’t) are nearly always tried before either a six person jury, or a Judge in a County Court at Law.
Again, regarding criminal matters, the USSC has said that the 7th amendment guarantees a jury of AT LEAST six (no ceiling has ever been determined) for any offense involving possible imprisonment. That’s true in federal or state court. Please note that a state may, at its discretion, expand that right, as TX has. In TX, even traffic court cases in JP Court have a right to a jury trial.
We’ll see if the USSC reverses itself and makes a 12 person jury a requirement. If the USSC has accepted the case, which it apparently has, then I can only assume that such a ruling/reversal is at least being considered.
As for the language thing, that should have been screened out during the “qualifications” part of the jury selection process, even before voir dire. Strange that it was missed.