Mobile App: Insufficient Privileges to change Lookup Field Value in Blueprint Transition

Mobile App: Insufficient Privileges to change Lookup Field Value in Blueprint Transition

Hi,
I'm using a blueprint within the official android mobile app. Within that blueprint, there is one transition during which the user is asked to change the value of a lookup field that is linked to a custom module. The prompt comes up fine but upon tapping the lookup field I receive a popup saying "Insufficient privileges to perform this operation. Please contact your administrator."

I'm using the app as the Super-Administrator of the CRM account. API access is enabled for that user and I encounter no such issue while using the same account within a browser. Hence, despite the error message, this should not be due to the CRM user lacking any sort of permission to do anything within CRM.