Hello,
Unfortunately the version of the multianswer import format included in core Moodle only support one cloze question per file.
I still have a modified version that permit to import multiple questions available in my Github here:
https://github.com/jmvedrine/moodle-qformat_multianswers
If you know how to add a plugin to your Moodle you can try to use it. It has not been updated for a while but should still work with Moodle recent versions.