Premium Plugin Updates Not Detected

By default, MainWP should support all premium plugins that use standard WP Update API.

Troubleshooting

First, go to the child site and see WP itself detects available updates the plugins in the issue.
If Updates are detected on the child site, MainWP Dashboard should detect them too. Resync your sites and recheck. If still not detected, check the enhance compatibility section.
If the updates are not detected by WP, try to force recheck by refreshing the WP Admin > Updates page in the child site. If updates show up in the child site, after your resync your dashboard, updates should show in there too. If they don't show up on the child site, you should report the problem to the plugin author.
If updates show up in the child site, but not in MainWP Dashboard after resync, check the enhance compatibility section.

However, if some authors decide to build a custom Update API, it may cause compatibility issues.

Enhance Compatibility

To enhance compatibility, we have a custom filter mainwp_request_update_premium_plugins where you can list plugins that MainWP doesn't see available updates for. To do that, please follow these steps:

Login to your MainWP Dashboard
If not already installed, install the MainWP Custom Dashboard Extension.

Next, copy the following code snippet to the PHP Section of the Custom Dashboard extension:

add_filter( 'mainwp_request_update_premium_plugins', 'myhook_mainwp_detect_premium_plugins_update', 10 );
function myhook_mainwp_detect_premium_plugins_update( $premiums ) {
   $premiums[] = 'custom-plugin/custom-plugin.php';
   return $premiums;
}

Update the code as per your requirements. This includes adding slug(s) of plugins that have problems with detecting updates. If you are unsure where/how to find you can contact the plugin author and ask for that info. In case you have to add support for multiple plugins, you can handle it like this:

add_filter( 'mainwp_request_update_premium_plugins', 'myhook_mainwp_detect_premium_plugins_update', 10 );
function myhook_mainwp_detect_premium_plugins_update( $premiums ) {
   $premiums[] = 'custom-plugin-one/custom-plugin-one.php';
   $premiums[] = 'custom-plugin-two/custom-plugin-two.php';
   $premiums[] = 'custom-plugin-three/custom-plugin-three.php';
   $premiums[] = 'custom-plugin-four/custom-plugin-four.php';
   return $premiums;
}

Once the code snippet is ready, Save it and resync your sites.

Alternatively, if you don't want to use the Custom Dashboard plugin, the code snippet can be added to the functions.php file of the MainWP Dashboard site active theme. If that doesn't help, please feel free to open a helpdesk ticket so we can take a look, but as mentioned earlier, in some cases, depending on the Update API, there might be no way to make it fully compatible.

Source Article: https://kb.mainwp.com/docs/premium-plugin-updates-not-detected/