In order to get a good performance of the Situm Mapping Tool application, we recommend taking into account the following settings regarding the management of the use of network data:

Go to Settings > Network & Internet (or some similar option) > Data usage

Then, deactivate the Data Saver.

You have to deactivate the Data Saver

Besides that, you can also deactivate this option on the Data Saver's App Settings in order to empower this action. Click on Unrestricted data access. 

After this, search for Situm Mapping Tool and enable this option. 

You can also access this option by Settings > Applications