Trouble with importing translated assets back into Guides

We have a connector set up from Guides to our translation vendor, Propio. We send 9 languages at once. Most of the languages are imported back in without an issue. For one language, we can see in the Translation Project that all the files have been translated. However, when I go back to Assets or Guides some of the dita topic don’t seem to be working. The Title in Assets says “null” and when I open the topic, it’s just a blank screen. Other topics are working. I couldn’t find a common denominator for topics that aren’t working. There are some folders where none of the topics are working, but others were some work and some don’t.

Has anyone had this issue, and if so how did you resolve it? Adobe has suggested sending only one language at a time, but we have 9 standard languages that we have to translate each document into, and sending one at a time is not feasible.