If your store sells through more than one channel, your catalog is lying to at least one of them. Not out of malice โ out of gravity. Every channel has its own quirks, and every edit made in one place is an edit forgotten in another.
Where drift comes from
Three sources: manual edits (someone changed a price on the Shopify admin while on lunch), integration lag (the sync ran six hours ago), and channel-specific overrides (a sale on the website that never expired).
The fix, in order of effort
Easy: pick one place as the source of truth. Every edit happens there. Everywhere else is read-only in your head.
Medium: reconcile weekly. Export prices from each channel, diff against source. Fix what drifted.
Hard: put a real sync layer between your source of truth and your channels, so human edits elsewhere are detected and either pulled in or flagged.
Mimnu is that sync layer. But even a Google Sheet and a Monday morning ritual will beat whatever you're doing now.