No webhook sent for Meta Graph API Click-to-Message ads

Question

Running into a unique issue here regarding Meta Graph API Webhooks, specifically for click-to-message ads. This is specific to click to message conversations - the app works perfectly for conversations initiated organically. The setup:

The user token used to generate the page access token has the following permissions: pages_show_list, ads_management, ads_read, business_management, pages_messaging, leads_retrieval, pages_read_engagement, pages_manage_metadata, pages_read_user_content, pages_manage_ads, pages_manage_posts, pages_manage_engagement, public_profile

The page access token generated via this user token has the following permissions: pages_show_list, ads_management, ads_read, business_management, pages_messaging, leads_retrieval, pages_read_engagement, pages_manage_metadata, pages_read_user_content, pages_manage_ads, pages_manage_posts, pages_manage_engagement, public_profile

The Meta application is subscribed to the following web hook fields feed, leaden, message_echoes, messages, messaging referrals

This setup works perfectly for messenger conversations that start organically. However, no message data is received via the web hook for those initiated via an advertisement (click to message). Only the 'referral': {'source': 'ADS', 'type': 'OPEN_THREAD'... web hook is sent, which has no details on the message itself. The same goes for outgoing messages in these threads - no web hook is sent for messaging_echoes.

The only workaround I currently have found that resolves this issue is to assign my personal Facebook account full admin (Everything) access directly at the page level or via the Business Manager that directly owns the Facebook page. Webhooks start firing for click to message ads once this is done.

However, if I am assigned full admin (Everything) access to the page through a partner Business Manager, the webhooks for click to message ads do not fire for click to message ads. They do fire for organic messenger threads.

Is anybody aware of a possible solution here?