Shopify inventory tracking turned off after I imported a spreadsheet
Products that were tracking stock correctly stopped being tracked right after your upload — no warning, no error. It's almost always a re-export that carried a blank tracker column back into Shopify. Here's how that happens and how to check for it before your next upload.
What you'll see
A product that used to show a real stock count now shows a dash, and the "Track quantity" toggle on that variant is off in the admin. Nothing in your import confirmation email calls this out as a problem — it just reports rows processed.
Imports overwrite the setting, they don't preserve it
Shopify's inventory and product import both read a column called Variant Inventory Tracker. When it contains the exact value shopify, tracking is turned on; when it's blank, tracking is turned off — for that upload, regardless of what the variant's setting was a moment before. An import is not a "patch" that only changes the columns you touched; every recognized column is written as given, blank included.
This matters because it's common to build an "update" file by exporting from somewhere other than a full Shopify products export — a fulfillment report, a POS system, or a trimmed-down spreadsheet someone keeps for pricing. None of those sources know about the tracker column, so it's absent or blank, and re-importing that file switches tracking off for every row it matches.
How to confirm and fix it
Open your import file and check the Variant Inventory Tracker column. If it's missing or blank for the affected SKUs, the fix is to rebuild the file starting from a fresh full products or inventory export from Shopify itself — which carries the current tracker value forward — rather than layering a partial file on top of your store.