Have you tried vestibular rehab? Essentially a series of eye tracking + neck mobility exercises that support the visual and vestibular system.
The way one ENT described it, I have 40% degradation on one side. If it’s constant, your brain adjusts and you are essentially ok. If something happens to vary that then your brain can’t adjust. My theory is that you add inflammation or migraines or epilepsy or all of it and the brain can’t compensate.