Devlabs Excel reports builder not storing uploaded sheets anymore

We are using the devlabs Excel Reports Builder add-on and since the Creatio upgrade to Version 7.17 or 7.18 it is not possible anymore to upload templates. The upload in itself seems to go well as there is no error message indicating otherwise. But the checkbox "Template uploaded" is not set to True and after generating the report it is obvious that the template was not uploaded because none of the uploaded changes are in the generated report.