sql server – How to get the Azure SQL maximum database limit?

We are 3rd party for the customer, and we implement the web application on the top of their ERP data. They migrated to Azure SQL (cloud) about 4 years ago. Currently, they observe performance problems, and it seems to be caused by being near the limit of the database size. I am not able to tell what is the actual size limit applied to the application database.

SSMS: When using Database Properties from the SSMS console, it shows:

When looking at the General tab it shows Size and Size Available

The Configure SLO tab say the maximum size 14 GB:

Azure SQL console: However, when talking to their ERP implementor, their database administrator says, it should be OK.

So, there are apparently two limits like 50 GB and 14 GB. Which of the limits applies to the web application that accesses the application database? Is the limit almost reached, or the SSMS shows a distorted view? Can that be the reason for the observed problems (like extremely slow SQL operations outside the set timeout)?