Hi partner,
Unfortunately, this is by design.
Currently background processes are not available in Unified Interface.
[View:https://github.com/MicrosoftDocs/dynamics-365-customer-engagement/issues/1111:750:50]
There is an unsupported way, you can refer to it.
[View:https://crmtipoftheday.com/1312/view-process-history-from-unified-interface-forms/:320:50]