There are 2 different approaches at the moment to temporarily fix this issue:
1.) Disabling the Kinsta cache plugin, then decompress and recompress the zip files.
2.) Unzipping the XML files locally, uploading the whole folder in the FTP uploads/immerseus/import directory, and choosing the “Read directory from uploads” option when importing seems to fix the problem and there is no conflict with Kinsta’s cache plugin.