@clucky
Sounds like you probably had all of these tests done, but the ones that stand out the most are low Vitamin D, low calcium, low vitamins B1, B6, B9, B12, and E can cause tingling or numbness. Other electrolyte and/or vitamin disbalances can also cause tingling sensation, in the absence of nerve damage or obstruction to blood flow. Here is a link to Copilot search showing 25 causes of tingling. It also mentions exposure to toxic substances, like mercury and lead:
https://www.healthline.com/health/tingling-in-hands-and-feet