See my response 

Main issue was special characters in the vendor names including a comma such as , inc or , ltd.   I could not just change the Vendor name in Shopify but had to delete all the products, edit vendor names in QB Pos, save a new file to export, remigrate...

Most of 32,000 products migrated from QB POS are not searchable or sellable from our tablets is though all are showing in the Admin on Shopify.com as Active, on POS sales channel and Ok to sell if out of stock.  What might be wrong?