Office 365 Message Encryption

Hi Everyone,

Anyone can help me with issue below? 

We have a default branded OME v2 template that we use for encryption with O365 Message Encryption. When we send emails to external O365 orgs, the msgs go with html Wrapper instead of ‘Inline Experience’.

I know this is an expected behavior with non MSFT domains like yahoo, gmail etc. My new test tenant is configured exactly similar to the production environment but with the test tenant, emails go to other msft external tenant in ‘Inline Experience’. 

I notice only one difference between the Production and test tenant which is ImageURL parameter when I run get-omeconfiguration | fl

Test tenant: ImageURL is blank

Production Tenant: some that url points to storage account, this is something automatically added when branded the template in 2018.

is there a method that I can $null ImageURL? Any thoughts? This is Not Image parameter. 

Moe