Hey,
Congratulations on your sponsor approval. It sometimes takes a few days for ecas to work, so it might be an explanation.
Sometimes it is also that the combination of name + file number is not correct.
So, depending on what you tried, here are the "right combinations":
*UCI + sponsor name ( only last name, no first name, initials etc) + sponsor information
or
*File number (starting with F) + applicant name (only last name, no first name, initials etc) + applicant information
Hope it works for you!
Good luck,
Sweden