Workaround: export partial TMs, for instance limit the search to all TM Entries in a specific source and target language only. If your TM is very big, you can limit the export further to TM entries that have been created in a specific period of time. For instance, all German to Spanish created in 2018. This is how this Search could look like:

Remember to click on
Export Result Set to export only the Result of your Search.