ACSauthManager.GetACSAppOnlyContext is unable to set external access policy since 08/04

We have been using PnP.Framework to set some properties for the sites once the site is provisioned and it was working fine until 08/04 but suddenly the process started failing when setting sharingcapabilities to disabled. Other things work fine with the same ACS context and it happens on 2 different tenants.

In the below code enabling custom scripts part of the code works fine but "siteProperties.SharingCapability = SharingCapabilities.Disabled;" part fails. We are getting a 401 Unauthorized when it tries to set this property.

using (var context = ACSauthManager.GetACSAppOnlyContext(GetAdminSiteUrl(item.siteUrl, log), ClientID, ClientSecret))
{
                    var tenant = new Tenant(context);
                    var siteProperties = tenant.GetSitePropertiesByUrl(item.siteUrl, true);
                    log.LogInformation("Enabling Custom Scripts");
                    tenant.SetSiteProperties(item.siteUrl, noScriptSite: false);
                    context.ExecuteQuery();
                    log.LogInformation("Setting external access policies");
                    if (!item.isExternal)
                    {
                        log.LogInformation("Request is not an external site, setting sharing capabilities to disabled");
                        siteProperties.SharingCapability = SharingCapabilities.Disabled;
                        siteProperties.Update();
                        context.ExecuteQuery();
                        log.LogInformation("Completed setting external access policies");
                    }
}

Start at ACSauthManager.GetACSAppOnlyContext and trace the Tenant site-property operations shown in the issue. Compare the successful noScriptSite update with the SharingCapability update, reproduce the 401 Unauthorized response across the two reported tenant scenarios, and confirm that external access policy setting works without regressing custom-script updates.