Delete out your ecom syndicator username & password and Save.
Then re-enter them and Save.
You should then get the "Free Tier Activated" alert.
Then check your marketplace settings -- Settings --> Marketplaces --> eBay --> Country to make sure that eCom Syndicator is selected and your CSV and eBay channel are selected. Save those settings.
Once you do, please try logging back into eCom Syndicator to see if the subscription message goes away. If not, please create a support ticket and include both your Sku Grid username and eCom Syndicator username so that we can forward the issue to the developers.