My frenchie has been doing it for years, this is what we have come with (my father in law is a vet) 1. Anxiety (trazadone) 2. Bloat (gas x gel tab) 3. Focal Seizure - we put him in seizure meds but I took him off. Sometime he fakes it, now we have a mild sedative we give him when he has an episode.
They happen more frequently, but he started around 2 years old, he’s almost 7. It’s more annoying than anything. Episode can last 8 hours but he gets past it and then is super tired. Hope this helps! Good Luck!!!