All offered modules are compatible with WHMCS v8.9. No updates have been released - if you are using the last available module version, the module is compatible with WHMCS v8.9.
It's not uncommon in this industry to encounter WHMCS modules designed for limited compatibility with newer WHMCS versions, thus often requiring compatibility updates and update purchases.
Our products, however, are engineered for broad compatibility. This is an advantage of our leasing model, which eliminates the reliance on revenue from update purchases.
We are aware of how time-consuming WHMCS updates are for highly customized installations. For this reason we put a lot of effort on backward compatibility and almost all our modules work from WHMCS version 6.0 up to the latest version. You can find the exact details about the compatibility of each module in our store: https://whmcs.deploymentcode.com/index.php?rp=/store/modules