I also am having a similar problem. I only have a little under 200 products so far and my product ids are in order starting at 100 to 291 at the moment. What is strange, the 200th product id would not export. I thought there might be something like a special character in the description so i copied the product and now it’s id is 4455 (since woocommerce assigned the id for me.) I deleted the old one with the 200 id. Now, the 4455 id product exports just fine, and the 200 id is still gone (as it should be now since it no longer exist), but wait, now product id 201 is missing from the export and it exported fine before deleting the 200 id. It should be on line 102 of the exported csv.
My thought is, the plugin has a glitch between the 101 and 102 lines of the export. Perhaps this repeats every 100 lines, so people with more products end up missing one product per 100. I am about 6 items short of testing this theory, as my export has not reached 200 lines yet.
