Hello Dave,
It showed no SKU, but says it is In Stock, but no stock levels show
That odd because the extension does not sync products configured without SKU.
For further troubleshooting, can you please get back to us with:
1. System Status Report:
Could you please share a copy of your site’s System Status? You can find it via WooCommerce > Status.
Select “Get system report” and then “Copy for support”.? Once you’ve done that, paste it here in your response.
2. Square settings:
A screenshot of your Square settings from WooCommerce > Settings > Square > Settings
If you don’t already have a screenshot service installed, you can try https://snipboard.io or https://skitch.com/.
You can share the direct link to the image as a response to this topic.
[Please redact any private details, including address, name, email address, transaction details, API Keys, Passwords, etc]
3. A screenshot of the Variable product that says In Stock
(General, Inventory and Variation tabs)
4. Enable logging, and Share logs for Square sync, please:
There’s built-in logging system enabled in the Square extension that could help you determine the cause of this behavior. If you haven’t enabled this already, you can enable this in (WooCommerce > Settings > Square) :

Link to image: https://d.pr/i/YAvv9A
Once enabled, this saves sync logs under WooCommerce > Status > Logs >. Search for? Square
logs in the drop-down at the top-right section and click on view
button. Please copy the logs you’re seeing and paste them as a response to this email.
This will help us track where the problem lies. Note that we will only be able to view logs for actions performed after logging has been enabled. So we wouldn’t be able to track behavior via log if that occurred before enabling logs for the same.