One answer that seems plausible is the reactivation of the Epstein-Barr virus that can easily happen with the challenge to a person's immune system by the Cov. vaccines and Covid illness and aftermath. The EBV has been associated with quite a few autoimmune diseases, some of which are associated with neurological sympoms. Many long haulrts I have communicated with on support goup sites online had EBV confirmed with tests and even obvious symptoms. i used a protocol designed to suppress EBV reactivatio and have improved, but am still really challenged by the resurgence of two old and one new autoimmune syndromes, A good resource is "Stuff that Works," an EBV research and support group. Facebook also has support groups: Covid Long-Haulers, Neuro V Long-Haulers, Neuro V-6+ Long-Haulers. All the best in finding answers and recovery to health.