Model size behaviour

Hello Community,

I have a master model which includes all of my company's data to be used internally, this model is ~500 MB in size with tables in import from Google big Query.

I have created a new model with just the two fact tables from the same model with maybe 5-10% more data because of infrequent data refresh on the master model exactly the same amount of rows

The problem is, the new model comes out ~1GB in size - actually I am less than 100 KB away from breaking the 1GB limit for Pro users.

I have no idea how this can happen? It's the same data and there is without a doubt less data in the model taking up 1 GB.
The 1 GB one doesn't even have measures, visualizations etc while the small one has 100+ pages and several 100 measures plus many dimensions

I need to find a solution otherwise I will loose my ability to upload the model when it break 1 GB

Has anyone experienced something similar?

EDIT: Any tips or thoughts on how to debug this would also be welcome