Hi,
please let us know below points.
1. What kind of data source you created?
2. What fields you have in your data/info source.
3. Have tested data at ECC side RSA3?
Below are useful points to load master text data to info object.
1. First we need to enable attribute text option at info object level and select required text(short/medium/long)
2. at ECC side you need to have same ecc fields which holds key and text(short/medium/long) description along language. Text data source always comes with mandate 5 fields.
so please recheck your data flow and find the mistakes