Parameter getting defaulted automatically - BI publisher

Summary:

When I run a report, one of the parameters is unusable because, after I select one value, it gets defaulted to "All"

The data model works fine before running the report, then it is also affected by the issue

Content (please ensure you mask any confidential information):

Hi all,

I've built a model that uses a few parameters:

In particular, the "Business Area/GF" one, which draws from Business Unit names, works fine in the data model but, as soon as I run the report, it works only once and then it always gets defaulted to "All" despite not having any default value specified.