This is very rare, but trigeminal neuropathy can be caused by numerous things. One of them is from IgM monoclonal intrusion for someone that has higher IgM antibodies (often associated with non-hodgkins lymphoma like Waldenstroms Macroglobulinemia (WM). This is a rare indolent (slow growing) lymphoma or blood cancer. I have it. My neurological manifestations are in the feet (24/7 foot/toe numbness). It's not bad yet but I'm aware of it. The IgM antibodies attack the myelin-sheathing of the nerves (anywhere in the body). I met another WM patient at the office and he had the same symptoms as you. We both are taking a WM targeted therapy drug called Brukinsa for WM AND it is 71.4% likely to resolve the neuropathy issue in an average of 4.6 months. They can run a IgM ANA test to see if you have an elevated number of IgM antibodies in the blood.

None of this helps you if you don't suffer from a blood disorder, but at least it might you frame your search to include blood-related possibilities. Good luck.